The old saw about the original Senators, "first in war, first in peace, and last in the American League," was true almost from the first, but has been greatly overinflated. When the American League declared itself a major league in 1901, it was considered important to make a good showing on the East Coast, so players from the 1900 Kansas City franchise were used to form a team in Washington, which had been a National League town until the league pared down to eight teams following the financially troubled 1899 season. The Senators finished last four times in their first nine seasons and didn't rise above sixth place until second-place finishes in 1912 and 1913. The major catalysts in the improvement were the ascendance to greatness of Walter Johnson, who emerged in 1910 as the AL's best pitcher, and the hiring of Clark Griffith as manager in 1912. Griffith acquired first baseman Chick Gandil and pioneered in the use of relief pitchers and in signing Carribbean talent. But the team's new respectability faded a bit over the next decade.

The 1924 hiring of the team's regular second baseman, the 27-year-old Bucky Harris, as player-manager brought instant results with a surprise World Championship in his first season at the helm. The foundation had been laid by Griffith, who had bought the team in 1920. Besides Harris and Johnson, the club featured offensive stars Roger Peckinpaugh (the 1924 MVP) and Hall of Famers Goose Goslin and Sam Rice. Star pitchers included Tom Zachary and Firpo Marberry, considered by most to be the first relief ace. The club repeated as AL champions in 1925 with the acquisition of Hall of Fame pitcher Stan Coveleski.

Washington finished lower than fourth place only once in the next seven years, and then had the city's best season in 1933, capturing the AL title with a team-record 99-53 mark under the leadership of shortstop Joe Cronin. But the club dropped to seventh place in 1934, the team's worst showing since 1916, and Cronin (Griffith's son-in-law) was sold to the Red Sox after the season. The Senators had only four more winning seasons over the next 26 years. The greater incompetence of the Browns and the Athletics generally kept them out of last place, but when the Browns won the pennant in 1944, the Senators finished last. They had finished second the year before, and they finished second in 1945, due to the confusion of the war years, but the hardships of the Depression and the war years cut into attendance and left Griffith, never financially secure, on shaky fiscal ground.

On Clark Griffith's death in October 1955, the club passed to his son, Calvin. The club had finished last that season, the first of four last-place finishes in the space of six years. Clark had pondered the signing of Josh Gibson and other stars of the Negro Leagues to bolster attendance in the 1930s and 1940s, but had ultimately decided not to challenge the unwritten color line; Calvin felt that the team's attendance problem stemmed from Washington's increasingly largely black population, who were less well-off and who tended not to support the Senators, although they had often packed Griffith Stadium for Negro League games. He began lobbying to be allowed to move the franchise to Minneapolis. At first the other owners refused to consider it; the nation's lawmakers were protective of their city's ballclub and often spoke threateningly of reconsidering baseball's anti-trust exemption should the Senators be taken from them. But the decision to expand gave the AL and Griffith a new option, and the AL expanded a year earlier than the NL to allow the Senators become the Minnesota Twins in 1961, replacing them in the capital with the expansion Senators. (SH)