The Allegheny Arsenal Explosion and the Creation of Public Memory

Today’s post was developed from a former exhibit titled ”Allegheny Arsenal Explosion and the Creation of Public Memory.” The exhibit was initially displayed at the National Archives at Philadelphia and was then featured online as a digital exhibit. In collaboration with the National Archives Web Division, the National Archives at Philadelphia has reformatted the content from an online exhibit to a blog post for better access. It features records from the National Archives at Philadelphia along with related records from the Library of Congress and Detre Library & Archives at the Heinz History Center


On September 17, 1862, a mix of anticipation and uncertainty filled the air as young girls assembled to collect their pay at Pittsburgh’s Allegheny Arsenal. In the 1860s, news trickled in by word-of-mouth, telegraph, and newspaper. For weeks, rumors swirled of a possible Confederate attack as Union and Confederate forces descended on western Maryland for what would become known as the bloodiest battle of the Civil War: the Battle of Antietam. 

As the battle shook western Maryland, the disaster at the Arsenal likewise rocked the Lawrenceville community when a pair of explosions killed 78 people. It’s unclear exactly how or why the explosions occurred, though some records reveal unsafe working practices and storage facilities. The tragedy at the Allegheny Arsenal was largely overshadowed by the Battle of Antietam; very few records of the disaster survived. This post interrogates the lack of documentation, explores the records that do exist, and features an interpretive painting of the explosion by Alina Josan.


Originally designed by Benjamin Latrobe, the Allegheny Arsenal was a fixture in the economic and social life of 19th-century Pittsburgh. Built in 1814, the arsenal supplied and communicated with the west from 38 hilly acres in Lawrenceville, Pennsylvania. 

The Allegheny Arsenal developed an important relationship to the Lawrenceville community. During the Civil War, many women and children worked at the Allegheny Arsenal filling cartridges, making harnesses, and handling live gunpowder. Overwhelmingly, the people who worked at the arsenal were of Irish-Catholic heritage and lived in Lawrenceville.

Both census and payroll records show that the daughters, sisters, and wives of the immigrant families performed dangerous munitions work at the arsenal to earn desperately needed income. Most relied on community members such as physicians and clergymen to provide character references before they could begin work. Employment at the arsenal enticed young girls, widows, mothers, and wives who struggled to make ends meet with husbands, brothers, fathers, and sons off to war.

Colonel John Symington commanded the Allegheny Arsenal at the time of the explosion. However, questions linger about his health, ability, and desire to command the arsenal. Less than a month before the disaster, the U.S. military’s retirement board denied Symington’s request for retirement. Rumors also circulated that Major Symington, the commandant of the arsenal, harbored Confederate sympathies.

These fears held some merit. Symington’s own son joined the Confederate forces, and his daughter married Confederate General William Boggs. These incidents inflamed community sentiments. Symington’s contentious relationship with the surrounding neighborhood and the divisions within his own family likely informed his request for retirement just weeks before the fateful explosion.

Townsend to Symington: “I have the honor to inform you that the President has approved the following finding of the Retiring Board in your case: That you are not incapacitated for active service and are capable of performing the duties of your office.”

Alexander McBride served as supervisor of the munitions laboratory that exploded in September 1862. McBride worked at the arsenal from the mid-1840s through the conclusion of the Civil War. His own daughter Catherine, age 13, worked filling small arm cartridges. In the chaos immediately following the blast, McBride searched for his daughter only to discover that she was among the victims killed by the exploding munitions. A devoted public servant, McBride worked hard petitioning the federal government for compensation for the victims and families for the rest of his life.

The Explosion and Public Memory

It’s believed that the explosions resulted from inadequate or unenforced safety standards surrounding the handling of live gunpowder at the Arsenal. Firsthand accounts reported that employees carelessly handled live gunpowder and often spilled or swept gunpowder onto the ground and into the roads extending outward from the Arsenal. The initial spark is believed to have been struck by a flinty rock on the road that led up to the door of one of the Arsenal buildings.

A sermon delivered by Reverend Richard Lea captured the terror of that day:

The uncertainly of human life was never more strikingly shown in this community than upon the memorable 17th day of September, 1862. The morning was calm and beautiful, and until noon nothing unusual occurred at the Allegheny Arsenal. It was pay day, and the noble Union girls who had toiled all the month, were rejoicing over the reception of the fruits of their labor. The shop had been swept, and among the leavings, some loose powder was scattered over the stony road winding around the beautiful grounds. A wagon was passing, when either the iron of the wheel or a horse’s shoe struck fire. In an instant, a terrific explosion was heard, shaking the earth, and inflicting injury upon the surrounding buildings. Amidst a dense column of smoke and a bright sheet of flame, were seen fragments of the building mixed with portions of the human frame, raising high into the atmosphere, and then falling in a horrid shower all around.

—Quote from “Sermon Commemorative of the Great Explosion at the Allegheny Arsenal at Lawrenceville, Pennsylvania, on September 17th, 1862.” (Record held by the Library of Congress)

The explosion reverberated throughout this community but was overshadowed in the local and national news by the Battle of Antietam. An article titled “Appalling Disaster! Explosion at the U.S. Arsenal” landed on the third page of the Pittsburgh Gazette the day after the explosion, while information about the Battle of Antietam was featured on the front page.

Although featured less prominently, the article about the explosion gave a vivid and harrowing account of the scene:

The most appalling sight was the burning bodies. In some places they lay in heaps, and burnt as rapidly as pine wood, until the flames were extinguished by the firemen. In other places, nothing could be seen but the whitened and consuming bones, the intensity of the heat having consumed every particle of flesh.

The same article that detailed the horrors of the loss of life also tried to assure the reader that the explosion would not hamper the Union war effort:

Lest parties abroad misapprehend the facts, it is necessary to say that but a very small fraction of the Allegheny Arsenal has been destroyed. The loss of material is nothing compared to the loss of life. The Arsenal, with its immense shops, stores, and munitions, may be said to be uninjured, and the Government will experience but a very slight interruption to its business in consequence of the accident.

In the wake of the disaster, Colonel John Symington sent a letter to Chief of Ordnance Brigadier General James W. Ripley in which he requested to move the munitions at the Allegheny Arsenal to another U.S. Arsenal.

Brigadier General Ripley responded on September 29, 1862, stating:

I have to acknowledge the receipt of your letter of this 24th inst. and to say that there is no place to which your surplus ammunition can be transferred at present. The manufacture of ammunition should not exceed your ability to store it in safe and suitable buildings.

The community had little time to process and mourn, as the war effort required that the Arsenal continue to produce munitions and supplies for the Union. 

Work and life continued in Lawrenceville despite the disaster, and a memorial to the 78 victims of the explosion was erected in 1863 at the Arsenal. The community lobbied the federal government to compensate the families of the victims of the explosion for years, which is evidenced by House of Representatives Report No. 1434, “Pittsburgh Arsenal Explosion,” published on June 19, 1882.

The report and accompanying bill (H. R. 6063) was brought to the House Committee on Military Affairs on August 3, 1882, where it was met with some scrutiny. Committee member Congressman Nathaniel J. Hammond of Georgia asked: “Does the gentleman desire to establish the principle that whenever any man is injured while in Government employment the Government must make a donation to him?”

Although Congressman Thomas M. Bayne of Allegheny City responded:

The accident was the act of the officer of the Government who had the matter in charge.… They were rendering, too, most important service to the Government, because that work had to be done, and it was faithfully done by these people. Through no fault of theirs they became the victims of this great destruction of life.

Ultimately, the Committee objected to the legislation, which would have provided $25,000 to the victims and families of this disaster, and the bill died. The explosion at the Allegheny Arsenal was overshadowed by the Battle of Antietam in 1862, and families of the victims continued to be forgotten decades later as the U.S. Government refused to recognize fault or provide them with compensation.

The community in Lawrenceville, Pennsylvania, continued to remember those they had lost. On May 27, 1928, the Sons of Union Veterans of the Civil War and its Ladies Auxiliary dedicated a new monument to the victims of the Allegheny Arsenal explosion.

Part of the monument reads:

Time and its destructive elements obliterated the inscription and names on the original monument erected on this plot in 1863, which was in memory of the victims who lie buried here. The present monument is erected to keep ever sacred the memory of all seventy eight who lost their lives in this explosion.

This monument continues to serve as a reminder, almost 100 years after it was erected, of the community’s response and desire to remember those they lost.

An article by Joseph Capozzi published by the Pittsburgh Press on September 15, 1987, also paid homage to the victims of the tragedy.

An Artist’s Tribute: Allegheny Arsenal Explosion Painting

In 2010, the National Archives at Philadelphia collaborated with artist Alina Josan to develop an exhibit about the Allegheny Arsenal explosion using records from the National Archives at Philadelphia along with related records from the Library of Congress and Detre Library & Archives at the Heinz History Center.

Josan was moved by the stark contrast between the way that the Battle of Antietam and the Allegheny Arsenal Explosion were documented and remembered. Many images and still photographs remain from the Battle of Antietam; however, no images survived that captured the tragic event at the Allegheny Arsenal. Drawing from the firsthand testimony of witnesses, newspaper accounts, and other written records of the explosion, this painting represents a modern artist’s rendition of the blast.

Alina Josan’s Artist Statement About Painting the Explosion

In her own words, Josan described the project:  

“Since completing my studies at Temple University’s Tyler School of Art in 2004, I have had the pleasure of working with several historic sites in Philadelphia, and creating interpretative illustrations for Eastern State Penitentiary, the Philadelphia Society for the Preservation of Landmarks and Bartram’s Garden.

The creation of an illustration of a historical event based on textual records and occasionally augmented by fragments of visual information always poses an interesting challenge.

When I began work on the project based on the Allegheny Arsenal explosion, I was aided by excellent sources that detailed the event, its context and impact, but offered very little description of the physical architectural space where the explosion took place.

The only images of the site I was aware of at the time were several photographs of a monumental gate.

I learned that the arsenal was populated by a series of buildings, including the main laboratory where the explosions took place so I researched similar complexes contemporary to this one. Fortunately, images of other arsenals that functioned during the Civil War were plentiful, and supplied me with a better idea of the architecture and materials used at the time. The neat pyramidal stacks of cannonballs and corrugated zinc roofing are examples of recurring details.

Since I could glimpse the façade of a building through the iconic gate, I decided to incorporate it into the drawing. An early draft had this building at the center of a group clustered just behind the gate.

When a map outlining the actual placement of buildings on the grounds turned up late during the process, along with a photograph allowing for greater scope, it finally became clear that there were two separate arsenal areas, each enclosed by gated walls and separated by the cobblestoned Butler Road.

The building I’d made the center of the complex turned out to be a storage building in the ‘upper arsenal’ and on the other side another gate, made of metal bars and bound by four posts led the way to the lower grounds and the location of the building that I set out to focus on. My initial view of the space was literally turned on its head!

The final version follows the map as closely as possible, while focusing on the laboratory building. In the moment depicted, the collapsed porch still fumes from the initial explosion and successive blasts are issuing from the building.

My hope is that this depiction of the event will help draw the viewer to the exhibit and continue to serve as a reference as more is learned.”

Read more about the1864 Washington Arsenal explosion in the Prologue article, Fireworks, Hoopskirts—and Death: Explosion at a Union Ammunition Plant Proved Fatal for 21 Women.

And to learn more about records at the National Archives related to the Civil War-era, visit us online.

One thought on “The Allegheny Arsenal Explosion and the Creation of Public Memory

  1. Great article. I did not know about this incident. Thank you for taking the time to research and write this.

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