In Washington Park on Chicago’s south side, there’s a low brick building with green trim that until 1905 stabled horses at the original Washington Park racetrack. In the south suburban town of Homewood, a street called Derby Avenue harks back to Washington Park’s second incarnation, which burned in 1977. Through mid-20th-century, Chicago attracted many of the best stables in the country every summer. The remains of the old tracks lie all over Chicagoland: Aurora Downs, Garfield Park, Harlem Race Track, Dexter Park, Brighton Park. Sportsman’s Park.