William Maurice Cowan, or “Mo” as friends and family call him, just landed the biggest job of his career.

Cowan, a native of Yadkin County who is a former top aide to Democratic Gov. Deval Patrick, was tapped by the governor on Wednesday to serve as interim U.S. senator for Massachusetts until a special election is held to fill the seat vacated by John Kerry’s confirmation as the nation’s new secretary of state.

Cowan, 43, became chief of staff to Patrick in 2010 after serving as chief legal counsel during the governor’s first term.

Growing up in Yadkin County, Cowan graduated from Forbush High School in 1987, went to college first at Duke University and then Northeastern University School of Law in Boston, Mass., and then he landed at the governors office in Massachusetts.

Cowan began his law career in litigation in Boston after law school. He then moved to another firm, Mintz Levin, where last year he began working with Gov. Patrick as general counsel.

“I am proud and delighted to appoint Mo Cowan as interim U.S. Senator from Massachusetts,” said Governor Patrick. “Mo’s service on the front lines in our efforts to manage through the worst economy in 80 years and build a better, stronger Commonwealth for the next generation has earned him the respect and admiration of people throughout government. The people of the Commonwealth have benefited from his wisdom and good judgment during his time in our office, and will again in the Senate.”

“I am honored and humbled by this appointment today,” said Cowan. “I pledge to you and the people of Massachusetts that during this interim period I will work as hard as humanly possible to perform my duties with the needs and aspirations of our state’s citizens foremost in mind.”

Cowan is connected to his past.

“I have a very fortunate opportunity and I don’t talke it lightly,” Cowan said in an exclusive phone interview. “I’m also a proud son of Yadkin County schools.

“Yes, I am very delighted for the education I received at Courtney Elementary, East Bend, and then Forbush,” Cowan said. “If it wasn’t for the teachers I had in Yadkin County I wouldn’t be as centered and grounded as I am,” he said. “From what I know about back at home, Yadkin County gave each child individual attention to help them accomplish the most possible.”

Cowan said, “Yadkin County schools opened up the door to my mind.”

In 2003, Boston Business Journal named Cowan to its list of “40 under 40”, a select group of younger business and civic leaders. Cowan is the former president of the Massachusetts Black Lawyers Association and the Northeastern Law School Alumni Association. He serves on the Board of Trustees of Northeastern University.

Coman is married to wife Stacy, and they have two sons.