As the Marine Corps Celebrates 250th Birthday, UMD Alum Preserves Its History

The United States will celebrate its 250^th birthday next July with much hoopla, but for many Marines, the more personal bisesquicentennial occurs on Nov. 10, the anniversary of the service branch’s founding. To mark the milestone, the History Division in August published one of its most significant books, “Semper Fidelis: 250 Years of US Marine Corps Honor, Courage and Commitment.” It is the Corps’ first complete historical text since 1969.

“There was no comprehensive history that includes everything that happened in Iraq and Afghanistan— literally a generation of Marines,” said Callahan.

A former aviator who wears a close-cropped haircut and neatly buttoned suit coat, Callahan, 55, is now engaged in an even more daunting challenge than the book: digitizing every record in an archive that includes 6,000 collections totaling 45 million pages, 4 million photos, 35,000 audio files and 30,000 maps—not to mention 19,000 films, some recorded on Vietnam-era reel-to-reel tape machines as large as a mini-fridge.

The materials reside in the History Division’s stacks, a half-acre expanse where the thermostat is set to 60 degrees and maximum 50% relative humidity. Here lie the official papers of every commandant, letters penned by combat Marines to their mothers and correspondences detailing scandals. (In 1987, for instance, a pair of apparently lonely Marines stationed in Moscow fell victim to a honeypot sting run by the Soviets, prompting frustrated veterans to send in letters suggesting how the Corps might restore its reputation.) The trove includes recently declassified combat records as well as voluminous “command chronologies”—reports written regularly to document the activities of every battalion and squadron and ultimately sent to the National Archives by law.

On the ground floor below the stacks, staffers receive all manner of ephemera donated by veterans and their survivors. Some packages arrive without return addresses; others are accompanied by mold or basement-dwelling organisms. (The office makes good use of its freeze dryer.) Many artifacts are returned to sender with a polite note. Three-dimensional donations like helmets and rifles are routed to the National Museum of the Marine Corps abutting the base.

Callahan, who grew up on Long Island and enlisted in the Marines because of their reputation for excellence, didn’t begin his career as a history buff. After graduating from the U.S. Naval Academy, he became a F/A-18D flight officer. Rising through the ranks, he mused about the human aspect of conflict and educated those in his command about the reasons behind their deployment.

During a 1999 bombing campaign over Serbia to protect Albanian Kosovars, for instance, he tutored his team about centuries-long ethnopolitical hostilities in the Balkans. “They really wanted to learn, not just put bombs on planes and fix engines,” he recalled.

To fulfill the Marine Corps’ career-broadening requirement, he completed a George Washington University master’s program, then taught history courses at the Naval Academy for three years. In 2008 he was deployed to Iraq, where he helped the Marines in Anbar Province to integrate with the Army headquarters in Baghdad.

After 22 years, he retired in 2014 as a lieutenant colonel and began teaching leadership courses at Marine Corps University at Quantico. He also developed curricula in war theory—how and why nations fight.

While teaching, Callahan met naval historian Jon Sumida, who balanced his work as a research chair on the campus with an appointment in UMD’s history department. 

“He cared deeply about military history and wanted our defense establishment to get it right,” Callahan said of Sumida, who died in February. 

In 2013, Callahan enrolled in a UMD doctoral program to study under Sumida. For nine years he shuttled between Quantico, College Park and Annapolis, where he lived with his wife and son. His dissertation focused on the Marine Corps’ warfighting doctrine, requiring countless hours in the History Division’s archives. Following graduation, he was appointed director and started managing the collections himself.

His office is split into three branches totaling up to 34 employees. A field team boasts military reservists authorized to work in combat zones to collect potentially historical documents. An archives team catalogues the collections and assists third parties like congressmembers, scholars and the press. A histories team produces books and conducts oral histories with high-ranking officers.

“Of all the services, the Marines are most in touch with their history and heritage,” said Chief Historian Seth Givens, who runs the latter branch: “History is what happened and why. Heritage is tradition, which is born from history.” 

Despite the deep pride that Givens and Callahan share, Callahan is not blind to Marine Corps missteps over time and seeks to ensure they don’t happen again, especially considering the cyber and information domains in which decisions once left to generals are now falling to lower-ranking officers and enlisted Marines. “Without a sound understanding of the history that underlies a geopolitical situation, the chances of coming up with an effective, durable solution is minimal—you might do a lot more harm than good,” he said.

Looking ahead, Callahan intends to cultivate a closer relationship with the Corps’ operational network, informing decisions about impending missions and producing quick-turn papers with historical context. In the meantime, he will continue using history to reinforce Corps culture. Even the little things, like naming buildings and tracing the roots of reconfigured units so they can fly proper colors, hold immeasurable value, he said. 

“There is not a Marine in the Corps who doesn’t take that very seriously, who doesn’t think our forefathers are looking down at what they’re doing today,” he said.