After trading hands multiple times between the British and the Spanish, Spain finally ceded Florida to the United States in 1821, and in 1823 the U.S. Army established Fort Brooke (later Tampa).

[7] The very next year Odet Philippe, a French Huguenot from Charleston, South Carolina became the first permanent, non-native resident of the peninsula when he established a plantation near the site of the Tocobaga village in Safety Harbor.

University of South Florida archaeologists excavated the site in 1977 after Alfred C. Wyllie discovered an underground ammunition bunker while digging a swimming pool on his estate.

Pioneer families like the Booths, the Coachmans, the Marstons, and the McMullens established homesteads in the area in the years following, planting more citrus groves and raising cattle.

Brothers James and Daniel McMullen [11] were members of the Confederate Cow Cavalry, driving Florida cattle to Georgia and the Carolinas to help sustain the war effort.

[citation needed] Tarpon Springs became West Hillsborough's first incorporated city in 1887, and in 1888 the Orange Belt Railway was extended into the southern portion of the peninsula.

A trip to the county seat, across the bay in Tampa, was generally an overnight affair and the automobiles that existed on the peninsula at that time would frequently become bogged down in the muck after rainstorms.

Hundreds of girls from the area's most prominent families formed a group called the Bomb-a-Dears, holding dances, socializing with recruits, and selling war bonds.

[22] The county operates a 21-acre (8.5 ha) living history museum called Heritage Village containing more than 28 historic structures, some dating back to the 19th century, where visitors can experience what life was once like in Pinellas.

[24] Elevation in the county ranges from mean sea level to its highest natural point of 110 feet (34 m) near the intersection of SR 580 and Countryside Blvd.

[25] Due to its small size and high population, by the early 21st century Pinellas County has been mostly built out, with very little developable land left available.

The county has maintained a fairly large system of parks and preserves that provide residents and visitors retreat from the city and a glimpse of the peninsula's original state.

[26] The 35 miles of beaches and dunes which make up the county's 11 barrier islands provide habitat for coastal species, serve as critical storm protection for the inland communities, and form the basis of the area's thriving tourism industry.

Connecting Clearwater Harbor to Boca Ciega Bay is a thin, approximately 3.5-mile (5.6 km) stretch of water known as The Narrows, which runs next to the town of Indian Shores.

Species of fish commonly caught in the waters surrounding the county include spotted seatrout, red drum or redfish, snook, pompano, sheepshead, Spanish mackerel, grouper, mullet, flounder, kingfish, and tarpon.

Like much of Florida, Pinellas County is home to several invasive species that propagate easily outside their (and their natural predators') native range.

Examples of invasive animals include the wild boar, which poses significant health and agricultural problems in Florida and can sometimes be found in Pinellas, and the monk parakeet, small flocks of which can sometimes be seen in flight or building nests on electrical poles or telecommunications towers.

[31] Pinellas gained some national attention as the home of the Mystery Monkey of Tampa Bay, a non-native, feral rhesus macaque that had been on the loose for approximately three years in the south of the county.

Pinellas County's geographic position- lying on a peninsula between Tampa Bay and the Gulf of Mexico introduces large amounts of humidity into the atmosphere and serves to moderate temperatures.

[59] In national politics, Pinellas County, was one of the first areas of Florida to break from the Solid South and elect Republicans to public office.

The original Interlocal Agreement, which described the legal basis, leadership and operations of the Cooperative, was signed by sixteen cities, the taxing district of Palm Harbor, and the County in 1989.

In 1885 the American Medical Society declared the Pinellas peninsula the "healthiest spot on earth",[78] which helped spur the growth of the tourist industry.

Long established communities, particularly Old Northeast in St. Petersburg, Pass-a-Grille in St. Pete Beach, Harbor Oaks in Clearwater, and old Tarpon Springs contain notable historic architecture.

Indian Shores is home to the Suncoast Seabird Sanctuary, currently the largest non-profit wild bird hospital in the United States and considered one of the top avian rehabilitation centers in the world.

CMA's best-known permanent resident, is Winter, a bottlenose dolphin who was rescued in December 2005 after having her tail caught in a crab trap.

Regardless of the specific city where they play their games, all of the professional teams claim "Tampa Bay" in their name to signify that they represent the entire area.

The PGA Tour plays its Valspar Championship annually in March on the Copperhead Course at the Innisbrook Golf Resort in Palm Harbor.

Beginning in Tampa, the line has daily freight rail traffic through Oldsmar, Safety Harbor, Clearwater, Largo, Pinellas Park, and into St. Petersburg.

As of 2012, proposals were being developed[90] by community leaders for a light rail system which would connect the regional core cities of Clearwater, St. Petersburg, and Tampa.

The Pinellas Suncoast Transit Authority (PSTA) operates 205 buses and trolleys servicing 37 routes across the county, with major stops at all commercial centers.