William "Mo" Cowan will hold the seat for less than five months until a special election June 25, The Boston Globe reported. Kerry, D-Mass., resigned this week after he was confirmed as U.S. secretary of state.
"He has been a valued ally to me and our work on behalf of the people of the Commonwealth," Patrick said of Cowan at a statehouse news conference. "In every step, he has brought preparation, perspective, wisdom, sound judgment, and clarity of purpose."
The appointment means the U.S. Senate for the first time in its history will have two African-American members serving at the same time. In December, South Carolina Gov. Nikki Haley named Tim Scott, R-S.C., to replace Jim DeMint, who resigned from the Senate.
Unlike Scott, Cowan apparently has no plans to run for the seat.
Cowan grew up in Yadkinville, N.C. He was the first person from his high school to attend Duke University, one of the most prestigious colleges in the south, and settled in Boston after receiving a law degree frm Northeastern Univeristy.
Patrick and Cowan became close when both were practicing law in Boston.
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