Moore took his oath office just after 12 p.m. on two bibles – one that belonged to his grandfather, a minister, and another once owned by Frederick Douglass, a Marylander who escaped slavery and went on to become an author and famed abolitionist.
The new governor was surrounded his wife and his children. His oath was preceded by the swearing in of his running mate, Aruna Miller. Miller is the first immigrant and first Asian American elected statewide in Maryland.
Before his inaugural speech, Moore attended a wreath-laying ceremony at the Annapolis City Dock, which was once a regional slave port and the site of a memorial to enslaved African Kunta Kinte, who arrived there in 1767 and was written about in Alex Haley's book "Roots."
Moore, a combat veteran and former CEO of one of the nation’s largest anti-poverty organizations, campaigned on creating equal opportunity for Maryland residents. He defeated the Republican candidate by a landslide.
Special guests at Moore’s inauguration included Maryland Rep. Kweisi Mfume, Attorney General Anthony Brown, former Lt. Gov. Michael Steele, and former Massachusetts Gov. Deval Patrick, who was the second Black governor elected in the nation's history in 2006.
Former NAACP president Ben Jealous, Baltimore Mayor Brandon Scott and former Lt. Gov. Kathleen Kennedy Townsend also attended.
Oprah Winfrey, former television host and media personality, who was an early supporter of Moore, also spoke at the inauguration.
The Associated Press contributed to this report