September 30, 1971. Top of the ninth, two out, and the home team is leading, 7 to 5. The fans, unable to contain themselves, spill over the fences onto the field, and at 10:11 p.m., the last game of the Washington Senators is lost by a forfeit, ending an era of the National Pastime in The Nation's Capital.

But before the Senators were, there were the Nationals and the Olympics; before Griffith Stadium and RFK, there were National Park and (honest) the Swamp Poodle Grounds. And, in the late 1930s and early 40s, there were the Homestead Grays, who played in Griffith Stadium when the Senators were on the road and drew the biggest crowds in the Negro National League.

Now, in "Rounding Third: Professional Baseball in Washington, 1879 - 1971," you can revisit October 10, 1924, when Muddy Ruel raced home from second in the 12th inning to give the Senators their only World Series; you can pore over the programs, scorecards and uniforms, the autographed team pictures, bubble-gum and tobacco cards, Ted Williams' warmup jacket and a painting of Walter Johnson's pitching arm; you can imagine what Josh Gibson might have done in an integrated world of baseball; and you can listen to the Senators' last game or a 1939 broadcast with commentary by Walter Johnson, "The Big Train," himself.

And fittingly, since the exhibition is in Woodrow Wilson House, you can see President Wilson's leather-bound season passes to the American sport.

Put together by fans Greg Kallen and Brian Price - with the help of the National Trust for Historic Preservation, which owns and runs Wilson House - the show includes the glory of the good years as well as the charm and hopefulness of the other years, proving that "First in war, first in peace - and last in the American League" doesn't tell it all. CAPTION: Picture, The homestead grays, scourge of the negro national league, in 1939, the first year of their nine-year championship streak. Catcher Josh Gibson, standing at left, and first baseman Walter (Buck) Leonard , kneeling fifth from left, were later placed in baseball's hall of fame.