The Hempstead Plains is a region of central Long Island, in what is now Nassau County, in New York State. It was once an open expanse of native grassland estimated to once extend to about 60,000 acres. It was separated from the North Shore of Long Island by the Harbor Hill Moraine, later approximately Route 25. The modern Hempstead Turnpike approximately traces the separation of the plain from the South Shore of Long Island. The east–west extent was from somewhat west of the modern Queens, New York City border to slightly beyond the Suffolk County border.

The Cradle of Aviation Museum is an aerospace museum located in Uniondale, New York on Long Island, established to commemorate Long Island's part in the history of aviation. It is located on land once part of Mitchel Air Force Base which, together with nearby Roosevelt Field and other airfields on the Hempstead Plains, was the site of many historic flights. So many seminal flights had occurred in the area that, by the mid-1920s, the cluster of airfields was already dubbed the "Cradle of Aviation", the origin of the museum's name.