Before Jillian Chaffee began her co-op in January at the United States Library of Congress in Washington, D.C., she had no idea who Antonio Augusto Carvalho Monteiro was.

But over the last few months a lot of her time has been devoted to searching the library’s vast collection for books, papers, and pamphlets that once belonged to the Portuguese millionaire who lived from 1848 to 1920. It has not been an easy task: All in all, the library houses more than 150 million items and is the world’s second largest library in terms of shelf space and number of books.

“When my supervisor called about the job, she described it as one big logic puzzle and I was sold,” said Chaffee, SSH’15. “This job is really fun because it’s super hands-on.”

Earlier this semester, Chaffee took to Twitter to share her experience of working in her “dream job” with the Northeastern community, tweeting “#Iheartcoop cause I spent the morning updating the Library of Congress database. I walk into work smiling every single day! #dreamjob.”

Chaffee, who is working for the collections officer in the Collections Access, Loan, and Management Division, is responsible for finding miss-catalogued pieces from Monteiro’s collection of 33,000 books, manuscripts, and pamphlets, which were sold to the library in the 1920s.

Chaffee pours through countless books looking for a specific stamp signifying a book or paper was part of Monteiro’s collection. How often she finds a book from the collection can be sporadic, but earlier this month Chaffee found 12 that belonged to Monteiro.

She is also tasked with examining books requested from the library’s famed Reading Room to determine their state of deterioration and what steps must be taken in order to preserve them. Some books she has handled include an Italian book published in 1526 and a Bible from 1871.

“Every Tuesday morning I go through a cart of incredibly old books, usually from the 1800s or 1900s, and decide if they need to be put in a box, envelope, or if they are too damaged to handle,” Chaffee said. “It’s been very cool.”

As an cultural anthropology and linguistics major, Chaffee is interested in how people interact and is constantly observing library visitors, of which there are more than 1.6 million annually.

“There is a very distinct style among the people in the Reading Room who dress in business casual compared to those who dress in jeans,” she explained.

Chaffee has always loved old books, but never considered working with them in a library until this co-op. “It’s been so much fun,” she said. “And it has taught me I was not meant to have a desk job.”