The National Building Museum in Washington, D.C., is hosting a new exhibition on public transportation and its effect on the development of cities. The show, “On Track: Transit and the American City,” opened Jan. 26 and runs through Oct. 27. The exhibition walks visitors through distinct “composite cities” depicting three major historical periods in transit’s history. “Expanding City” (1880-1920s) covers transit in its infancy, with the introduction of electric railways and the conversion from horse power to electricity. The section explores the new-found mobility Americans discovered as cities developed from “walking cities,” as transit — and the automobile — began to take hold. “Suburban City” (1920s-1960s) shows the rise of suburbanization and sprawl, along with the decline of electric rail transit systems, accompanied by the decline of American cities. “Regional City” (1960s to present) focuses on the re-emergence of rail transit in America and the introduction of multimodal forms of transportation. The exhibition was organized by the museum’s curator, Mary Konsoulis, and Kathleen Franz of the University of North Carolina, Greensboro. Sponsors include the American Public Transportation Association, the Federal Transit Administration and the Washington Metropolitan Area Transit Authority.