The American League officially formed for the 1901 season, with the Washington Senators becoming one of the staple teams. They would be known as a second division club, even though they won AL Pennants in 1925 and 1933 and a World Series Championship in 1924. They lasted until the 1960 season, where they officially became the Minnesota Twins. However, according to the official history of baseball franchises, an expansion team was started for the 1961 season with the same name, the Washington Senators. That franchise lasted through the 1971 season and is now known as the Texas Rangers. Of course, the Washington Nationals are a NL team that moved to DC for the 2005 season. This is the continuation of the Montreal Expos franchise that originated in 1969. So, if the current Nationals team is a continuation of the Expos team that started in 1969, an existing Washington baseball franchise has existed since 1901. Unfortunately, it is not that simple.
I never understood why the Twins could not be the expansion team in 1962. I mean, they were, along with the Los Angeles Angels, the two additional AL teams that were not in the league in 1960. But, the Twins were the Senators and a "new" Senators team took over in Washington. The history of the original Senators team moved to Minnesota with the Twins. The Twins technically have 3 World Series Championships (1924, 1987, 1991) and 3 AL Pennants (1925, 1933, 1965). The next Senators have their own history, starting from 1961-1971 with the Senators and moving to Texas, becoming the Rangers in 1972. That separate team has 2 AL Pennants (2010, 2011) and 0 World Series Championships.
The Montreal Expos came into the NL in 1969 and won the 2nd half of the NL East in the strike disturbed 1981 season. They had a lead in the NL East in 1994 when the players strike ended the season. The team was dismantled and they never returned to prominence before they moved to Washington. Since then, they won the NL East in 2012. Once again, this Washington team has no connection to either of the two AL franchises. This Washington team has 2 division titles (1981, 2012).
In the new age of interleague play every day, the separation between the AL and the NL is shrinking. It would all be the same had the AL not adopted the DH in 1972. I wonder if there will be a time where the history of the Washington franchise will become one. Make the Twins (1961+) and Rangers (1972+) their own expansion teams. At least that would be a start. Furthermore, if the NL Washington team merges its history with the two prior AL clubs, (1901-1960, 1961-1971, 2005+), it combines a history that has value to the District of Columbia. Plus, it would be nice to talk about how Washington has not won a World Series Championship since 1924 and a Pennant since 1933. Even the Cubs have won a Pennant since (1945). The easy defense is the gap without a team from 1972-2004.