Mark Sweeney Named Principal Deputy Librarian of Congress

Librarian of Congress Carla Hayden today announced that Mark Sweeney will serve as Principal Deputy Librarian of Congress.

Sweeney has served as Acting Deputy Librarian of Congress since September 2017.

“Mark has been a dedicated public servant and leader at the Library for three decades,” Hayden said. “He brings an in-depth understanding of the institution and our staff to this office, and I am so pleased he has agreed to accept this permanent appointment. We have such exciting things in store for our users in the coming years and Mark will play a central role.”

The role of Principal Deputy Librarian is to assist with managing the Librarian’s priorities and function in a strategic role, working closely with senior leadership internally and high-level individuals externally. The Principal Deputy Librarian provides executive leadership and broad oversight to the heads of the U.S. Copyright Office, the Congressional Research Service, the Office of the General Counsel and the Deputy Librarian of Library Collections and Services Group. 

Before his appointment as Acting Deputy Librarian, Sweeney served as Associate Librarian since August 2014 - first on an Acting basis then as permanent appointee beginning in February 2015. Previously, Sweeney served as the Library’s Director of Preservation beginning in April 2012. Prior to that, he served for nearly five years as the Chief of the Serial and Government Publications Division, followed by seven months as Chief of the Library’s Humanities and Social Services Division.

During his 30 years with the Library of Congress, Sweeney has also served as Program Manager for the Library’s highly successful National Digital Newspaper Program, as Chief of the Preservation Reformatting Division, as Head of the Newspaper Section, as a Reference Specialist and as a Supervisory Library Technician.

He has presented at numerous professional meetings and served on national and international boards and committees.

Sweeney holds a Bachelor of Arts degree in history from McGill University and a master’s in library and information science from the Catholic University of America. 

The Library of Congress is the world’s largest library, offering access to the creative record of the United States - and extensive materials from around the world - both on-site and online. It is the main research arm of the U.S. Congress and the home of the U.S. Copyright Office.  Explore collections, reference services and other programs and plan a visit at loc.gov, access the official site for U.S. federal legislative information at congress.gov and register creative works of authorship at copyright.gov.