Federal Triangle (Between Pennsylvania Ave, Constitution Ave & 15th St NW)
During the Civil War, prostitutes flooded Washington to take advantage of an influx of businessmen, government beaurocrats, and especially Union soldiers. By 1863 it was estimated that 5,000 prostitutes were living and working in the city.
When the war ended, DC remained over crowded. The section between Pennsylvania Avenue and The Mall (known today as Federal Triangle) had become an infamous neighborhood rife with crime and prostitution. District residents called the area Hooker’s Division. This was a clever play on words that referred to both the prostitutes that occupied neighborhood and their frequent customers–the troops in General Joe Hooker’s division–that were camped nearby.