WASHINGTON – Carla Hayden officially made history at midday on Wednesday, becoming the first woman and first black librarian of Congress.

Hayden was sworn in as the 14th head of the 200-year-old institution at a time when the library is transitioning into the digital age. Its technology and modernization efforts have come under criticism from Congress and the Government Accountability Office.

Hayden emphasized moving the institution forward and making its 162 million items more accessible.

"This is the opportunity to build on the contributions of the librarians who have come before, to realize a continuing national library vision that reaches outside the limits of Washington," Hayden said.

Hayden succeeds acting librarian David Mao, who had served since James Billington retired last September. She will be the first librarian of Congress to have a term limited to 10 years. The post had previously been a lifetime appointment. Hayden can be renominated for the position.

The magnitude of the occasion was not lost on Hayden or the audience gathered in the great hall of the library's Thomas Jefferson building. The crowd cheered after Hayden said, "As a descendant of people who were denied the right to read, to now have the opportunity to serve and lead the institution that is our national symbol of knowledge, is a historic moment."

Some library workers have pointed out that the institution has struggled with diversity and discrimination issues within its workforce, and were hopeful that Hayden might be able to bring change.

Speaker Paul Ryan addressed the ceremony, along with Sen. Roy Blunt, R-Mo., chairman of the Senate Rules and Administration Committee, and retiring Sen. Barbara Mikulski, D-Md. Mikulski and Sen. Benjamin Cardin, D-Md., recommended that President Obama nominate Hayden for the position. Mikulski recalled that when senior Obama adviser Valerie Jarrett called to inform her that the president was considering Hayden, Mikulski thought, "That's like bringing Cal Ripken back to the Orioles!"

Hayden has led the Enoch Pratt Free Library in Baltimore since 1993. She worked to keep a library branch open when riots rocked the city after Freddie Gray died in police custody. "Cars were still smoldering in the streets. Closed signs were hanging in storefronts for blocks. But people were lined up outside the doors of the library," Hayden recalled. "And I remember a young girl came up to me asking, 'What's the matter? What is everyone so upset about?' She came to the library for sanctuary and understanding."

Hayden previously led the American Librarian Association. She began her work as a librarian in the Chicago Public Library system.