The character of New York's large residential districts is often defined by the elegant brownstone rowhouses and townhouses and shabby tenements that were built during a period of rapid expansion from 1870 to 1930. In contrast, New York City also has neighborhoods that are less densely populated and feature free-standing dwellings. In neighborhoods such as Riverdale (in the Bronx), Ditmas Park (in Brooklyn), and Douglaston (in Queens), large single-family homes are common in various architectural styles such as Tudor Revival and Victorian.
Brownstone rowhouse construction is most often associated with the period beginning in 1870 and ending in what year?
1930