Built between 1585 and 1593, the walls of Bely Gorod helped defend which city?

Building on the work of Galileo and Kepler, who published the first quantitative theory of gravitation in 1687? Built around 1600, which Venetian bridge links the Doge's Palace with the nearby prisons? Built around 1776, Tank Cottage is said to be the oldest house in Wisconsin. In which city is it? Built around 1830, which early American steam locomotive shared its name with a tiny P.T. Barnum star? Built between 1732 and 1756, which Philadelphia building appears on the reverse of the Bicentennial half dollar? Built between 1817 and 1825, it was 363 miles long, 40 feet wide at the top and 4 feet deep. What was it? Built between 1891 and 1916, the Trans-Siberian Railway runs east from Chelyabinsk to which Pacific city? Moton Field in Alabama, built from 1940 to 1942, has a national historic site honoring which famed group?