The Redskins began as a Boston team - set up in 1932, playing at "Braves Field", the Baseball stadium. They took the name the 'Boston Braves'. When they moved to Fenway Park the following year, they changed their name to the 'Redskins' (Fenway Park is the home of the Boston Red Sox).
In 1937 the franchise moved to the Capital, becoming at last the 'Washington Redskins'.
The Redskins last won a Superbowl in 1992 - you can read the Washington Post report on this victory at http://www.washingtonpost.com/wp-srv/sports/redskins/longterm/1997/history/allart/xxvi.htm.
Here's hoping that the team will return to its winning ways.......soon!