William “Mo” Cowan sworn in as new senator from Massachusetts

William “Mo” Cowan. PHOTO/AP

William “Mo” Cowan of Massachusetts is the Senate’s newest member.

The 43-year-old Democrat took his seat Thursday after a swearing-in ceremony led by Vice President Joe Biden. Cowan succeeds Democrat John Kerry, who just took over as secretary of state.

Cowan’s swearing-in makes him the eighth African-American senator in U.S. history. There are now two serving African-American senators, one Democrat and one Republican (South Carolina Sen. Tim Scott). This will be the first time in U.S. history that two African Americans have served in the Senate at the same time. Scott was also a gubernatorial appointee to his seat.

Cowan was picked by Democratic Gov. Deval Patrick to serve as interim senator until after a special election June 25. Cowan had stepped down as Patrick’s top aide last December.

Cowan is the state’s second African-American senator. Republican Edward Brooke served from 1967 to 1979.

Cowan was a partner in a Boston law firm before going to work for Patrick.

Copyright 2013 The Associated Press.