AAA Editor Notes
The Loop is bounded by the Chicago River on the n. and w., Roosevelt Rd. on the s. and Lake Michigan on the e. America's second largest downtown business district is home to historic high-rises, several government buildings and the theater district. The Loop took shape in the late 1800s as early urban transportation plans centralized commercial enterprises within a .5-mile square that pedestrians, horse-drawn carriages and streetcars shared. In 1897 the opening of the elevated Union Loop railway further defined the city area.