President-elect Donald J. Trump on Monday has chosen Dr. Ben Carson to be his housing secretary and is set to formally select the retired general James N. Mattis to be his defense secretary. Carson, who challenged Trump during the Republican primary, is the first African-American selected to serve in the president-elect's Cabinet. "I feel that I can make a significant contribution particularly by strengthening communities that are most in need." Carson said. "Ben Carson has a brilliant mind and is passionate about strengthening communities and families within those communities," Trump said in the statement.