The Portland City Council purchased the present PDX site in 1936. It was bordered by the Columbia River in the north and the Columbia Slough in the south. The city council issued US$300,000 and asked the Port of Portland to sponsor a US$1.3 million Works Progress Administration (WPA) grant to develop the site into a "super airport". The project provided badly needed Great Depression-era jobs. Construction of the airport steadily employed over 1,000 men, and was described by historian Neil Barker as "Portland's most significant public works improvement during the New Deal era". The WPA and Port of Portland faced difficulties in preparing the site for construction because the low-lying area was frequently covered by flood waters from the Columbia River. Workers covered the area with over of sand to help drain it of water, and constructed a series of dikes to control flooding. Two runways capable of serving the modern aircraft of the time were operational by 1941. The airport was designated Portland–Columbia Airport to distinguish it from then-operating Swan Island Airport. During World War II, the airfield was used by the United States Army Air Forces.