Until last week, the Nationals were the only big league club the 26-year-old Harper had played for, an organization that drafted him No. 1 overall in 2010 and brought him to the majors as a teen. Washington's uniform was the one he wore when he won NL Rookie of the Year and MVP honors, when he earned six All-Star selections in seven seasons — including last year, when he stole the show by winning the Home Run Derby in D.C.