Since its incorporation in 1902, the city's population has grown dramatically as it annexed nearby unincorporated areas. The city's July 2014 population (not including East Porterville) was estimated at 55,466.

Porterville serves as a gateway to a vast wonderland and recreational area, the Sequoia National Forest, the Giant Sequoia National Monument and Kings Canyon National Park.

During California's Spanish period, the San Joaquin Valley was considered a remote region of little value. Emigrants skirted the eastern foothills in the vicinity of Porterville as early as 1826. Swamps stretched out into the Valley floor lush with tall rushes or "tulares" as the Indians called them.

Gold discovered in 1848 brought a tremendous migration to California, and prairie schooners rolled through Porterville between 1849 and 1852. Starting in 1854, Peter Goodhue operated a stopping place on the on the bank of the Tule River. Wagon trains of gold seekers passed through the village, but other travelers found the land rich and remained to establish farms. A store was set up in 1856 to sell goods to miners and the Indians, who lived in tribal lands along the rivers. From 1858 to 1861 it was the location of the Tule River Station of the Butterfield Overland Mail.

Royal Porter Putnam came to the village in 1860 to raise cattle, horses and hogs. Putnam bought out Goodhue in 1860, turning the station into a popular stopping place and hotel called Porter Station. He bought 40 acres of land and built a two-story store and a hotel on the highest point of the swampy property, which is now the corner of Oak and Main. The town of Porterville was founded there in 1864. The town took its name from the founder's given name because another Putnam family lived south of town.

...
Wikipedia