Fort Pierce is a city in and the county seat of St. Lucie County, Florida, United States. It is also known as the Sunrise City, sister to San Francisco, California, the Sunset City. The population was 41,590 at the 2010 census. As of 2012, the population recorded by the U.S. Census Bureau was 42,645. It is named after the army installation of Fort Pierce built in the area in 1838 during the Second Seminole War.Fort Pierce was awarded the 2005 City of Excellence Award by the Florida League of Cities for overall excellence in city government and in 2011, Main Street Fort Pierce, Inc. received the Great American Main Street Award from the National Trust for Historic Preservation in downtown.