Mark Sweeney, the principal deputy librarian for the Library of Congress, enjoys an expansive view of Washington, D.C., from the balcony outside his office (Photo: Shawn Miller/Library of Congress)


Helping to run the world’s biggest library

As the principal deputy librarian for the Library of Congress, Mark Sweeney, BA’84, plays a senior role in overseeing an institution with one-of-a-kind treasures used by everyone from Members of Congress to high school students to Lin-Manuel Miranda.

Story by Judith Ritter, MA'72

August 2018

Thirty-three years ago, newly minted McGill grad Mark Sweeney, BA’84, moved to Washington, D.C. for his first “real” job. Every day from 1 pm to 9:30 pm, he sorted, organized and shelved books in the world’s largest library, the Library of Congress.

With about 1,300 km of bookshelves to work with, he kept busy. Sweeney found the job pleasant, but more importantly, the hours were perfect. The afternoon shift, he says, left his mornings free to search for what he called his “Washington dream job.”

Today, sitting in his office overlooking the U.S. Capitol Building, he acknowledges that his dream job had been a lot closer than he realized back then. “What I did find was the Library of Congress,” says the library’s new principal deputy librarian.

From his very first visit, Sweeney loved being in a place where there are close to 25 million books, 10 million pages of newspapers, and, with five million maps, the finest cartography collection in the world. That hasn’t changed. When he welcomes visitors to the library to show off the venerable institution’s unique holdings, there is palpable joy in his voice.

With unabashed, almost boyish excitement, Sweeney points out several treasures: In the manuscript division, the papers of 23 of the U.S. presidents, from those of George Washington to Calvin Coolidge; a touching section of Teddy Roosevelt’s diary about the death of his daughter and wife on the same day; a centuries-old Gutenberg Bible; the contents of Abraham Lincoln’s pockets the night he was assassinated; and the original map that explorers Lewis and Clark used and on which they annotated their discoveries.

And, yes, there are some Canadian treasures too, including the 1607 Samuel de Champlain map of Montreal. “If you love history, it comes alive here!” says Sweeney (he majored in history at McGill).

Sweeney was born in Nebraska and grew up in Connecticut. His father had developed a fondness for Canada and Canadians as a young man while studying in a seminary in Buffalo near the border. When it was time for Mark to head off to university, his dad urged him to consider Canadian options. Once Mark visited McGill and Montreal, it was a coup-de-foudre (love at first sight).

“There was so much going on in Montreal – the PQ, the referendum and economic changes! Montreal was a little gritty and very cosmopolitan. The city just grabbed me.”

His favourite spot on campus was the Redpath Museum. “Walking into that museum was as if you were in Raiders of the Lost Ark – dinosaur bones, a mummy. I thought, ‘Gosh this is just wonderful and you can walk in any time.’”

Over his three decades at the Library of Congress (with a break to complete a master’s degree in library and information science), Sweeney has served in a variety of positions. Among his roles and duties, he was the library’s director for preservation, responsible for protecting the collection for posterity. That meant overseeing everything from binding to emergency response planning.

As the head of the newspaper section and as program manager for the library’s National Digital Newspaper Program, he was the guardian of newspaper issues dating from the 18th century and responsible for and involved in identifying thousands of old newspapers. He also supervised a project to digitize the papers, making them more easily accessible to the public.

In his current position as principal deputy librarian (he had been in the role on an acting basis since last September), Sweeney takes on senior executive duties for an institution whose unique collections include everything from rare cuneiform tablets to presidential tweets. His responsibilities include providing broad oversight to the heads of the U.S. Copyright Office and the Congressional Research Service.

The library’s 17 reading rooms (including rooms dedicated to cartography and science) are a resource for Congress as well as the public. The library regularly welcomes a variety of visitors, from members of Congress and their aides to students working on school projects.  Literary and artistic luminaries such as Pulitzer Prize winner and historian David McCullough, filmmaker Ken Burns and Broadway star Lin-Manuel Miranda have been spotted in the library’s music and manuscript division.

As the venerable library zooms into the digital sphere, high-tech transformation is the order of the day, as well as projects aimed at broadening access to the collections. Sweeney wants more people to know about the treasures, maps, manuscripts and objects that have fascinated him for 30 years, including the little-known fact that the library has the world’s largest comic book collection.

Is the second in command of the world’s largest library a bit of a comic book geek? Yes, indeed. Sweeney admits that he has been known to sneak a peek at rare editions of some of his favourite superhero adventures. He could argue that it’s part of his job.

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