By Melissa A. Winn
While recently discussing Civil War research with Military Images Editor Ron Coddington, our conversation took an unexpected turn.
“While editing,” he remarked, relaying his work on a story about a Signal Corps officer, “I suddenly became interested in pyrotechnics.”
As I told Ron, that might be my new favorite sentence, because that’s the story of so many of us Civil War enthusiasts. The rabbit holes are endless. A passing curiosity suddenly becomes an obsession, leading to forgotten inventions and overlooked lives. In this case, it was Martha Coston, whose incredible story Ron stumbled upon. He promptly introduced her to me, and my curiosity was immediately piqued. Even after years of studying Civil War women, it amazes me to discover such a remarkable figure whose extraordinary achievement has largely vanished from public memory.
Few Americans recognize the name Martha Coston, but her invention helped the Union Navy communicate across dark waters, tighten the blockade, coordinate military operations, and ultimately save countless lives.
At just 21 years old in 1848, Martha Jane Coston found herself in desperate circumstances. Her husband, Benjamin Franklin Coston, a gifted inventor and scientist employed by the U.S. Navy, died. Left with four young children and virtually no financial resources, Martha sought a way to provide for her family. Knowing that her husband’s pivotal but unfinished work held great promise, she searched his papers.
“At last I came upon a large envelope containing papers and a skillfully drawn plan of signals to be used at sea, at night, for the same purposes of communication that flags are used by day,” Martha wrote in her autobiography, A Signal Success: The Work and Travels of Mrs. Martha J. Coston.
Turning her husband’s research into a practical signaling system required years of experimentation, persistence, and personal sacrifice. Martha hired chemists, consulted pyrotechnic experts in Europe, financed repeated experiments, and endured countless disappointments.
“It would consume too much space and weary my readers, for me to go into all the particulars of my efforts to perfect my husband’s idea,” she recalled in her book, describing “the men I employed and dismissed, the experiments I made myself, the frauds that were practised upon me.”
The result was the Coston night signal and code system—a series of brightly colored pyrotechnic flares that communicated messages through combinations of red, white, and green lights. Each sequence represented numbers corresponding to naval signal books, allowing ships to exchange detailed messages after dark. As Martha explained, “The Coston Signals consist of a colored firework, or a combination of not more than three colors, contained in a small metal case, and they designate by the order of the colors burnt the number to be understood.”
Recognizing its value, the U.S. Navy tested the system in the late 1850s and officially adopted it shortly before the outbreak of the Civil War.
Throughout the Civil War, Martha Coston’s flares became standard equipment aboard Union naval vessels.
The timing could not have been better.
Throughout the Civil War, Coston flares became standard equipment aboard Union naval vessels. Blockading squadrons used them to coordinate patrols along thousands of miles of Confederate coastline. Ships exchanged tactical information after dark, summoned assistance, warned of danger, and identified friendly vessels.
Martha wrote, “Before proceeding with my story, it will, I think, be of interest to my readers to know exactly what part the Coston Telegraphic Night Signals played during that terrible civil convulsion of our country. In the first place, nearly all the blockade-runners were caught by their use, as they generally made their runs by night, and the United States navy vessels gave chase after communicating with each other by means of the signals. Numerous battles and bombardments were successfully conducted through this ready means of communication.”
“In the darkness of night, in storm of ocean, in battle and quiet; at all distances limited by the horizon the Coston Signal ever efficiently did its work,” a testimonial from Aaron Vanderbilt, an officer on the staff of Adm. David Porter during the war, said.
Martha did far more than invent the system. She founded the Coston Manufacturing Company, supervised production, and personally negotiated contracts with the federal government. These tasks placed her in a world almost entirely dominated by men.
Despite the Navy’s enthusiastic use of her invention, Martha spent years fighting for fair compensation. Government officials repeatedly challenged her patent claims, questioned her pricing, and delayed payments. Much of the dispute centered on the fact that Benjamin had originated the initial concept, even though Martha had transformed the unfinished sketches into a functioning military technology through years of independent experimentation.
She pursued claims before Congress and government boards for decades, receiving only a fraction of what she believed she deserved. Her experience reflected the legal and cultural barriers faced by many 19th-century women whose intellectual contributions were frequently minimized or attributed to male relatives.
Yet Martha refused to disappear quietly.
She aggressively marketed her signal flares internationally, securing sales to foreign navies and commercial shipping companies. By the late 19th century, Coston flares had become an internationally recognized standard for maritime signaling. Variations of her system remained in military and civilian use well into the 20th century, influencing modern emergency signaling equipment still carried aboard ships today.
Martha Coston died in 1904, but her company, later called the Coston Signal Company and the Coston Supply Company, remained in business until at least 1985.
Her 1886 autobiography includes detailed descriptions of her fight, as a woman, to be recognized and compensated fairly for her work as an inventor. She always had to be “ready to fight like a lioness,” she said. The revered inventor Samuel F.B. Morse called her “the accomplished inventress.”
In 2006, Martha Coston was inducted into the National Inventors Hall of Fame.
Melissa A. Winn has been enchanted with photography since childhood. Her career as a photographer and writer includes numerous publications, among them Civil War Times, America’s Civil War, and American History magazines. She is currently Director of Marketing and Communications for the National Museum of Civil War Medicine. Melissa collects Civil War photos and ephemera, with an emphasis on Dead Letter Office images and Gen. John A. Rawlins, chief of staff to Gen. Ulysses S. Grant. Melissa is a MI Senior Editor. Contact her at melissaannwinn@gmail.com.
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