Tampa remained a compact city with a land area of until the mid-1950s. Its northernmost boundary was the Hillsborough River, in the northern part of the Seminole Heights neighborhood. In 1953, the city annexed over of unincorporated land, including the communities of Sulphur Springs and Palma Ceia. As a result, Tampa grew rapidly, growing by 150,289 residents during the 1950s. The growth also reflected on the city's national ranking. Tampa jumped from 85th in 1950 to 48th in 1960. its peak ranking to date.