In 1836 Porter County was formed, including the territory now comprising both Porter and Lake Counties, with Portersville as the county seat. In 1837, at the suggestion of the residents, the Indiana General Assembly changed the name of the county seat to Valparaiso, which is Spanish for "Vale of Paradise", to symbolize the beauty and wealth of the lakes and beaches and rich agricultural land surrounding it.
Porter County was named in honor of Commodore David Porter of the U.S. Navy, whose famous battle during the War of 1812, while in command of the Essex, was fought near the harbor of Valparaiso, Chile. Commodore Porter captured seven British ships and took possession of the Marquesas Islands during this great exploit. Eventually, the Essex was blockaded by British ships in the harbor at Valparaiso and Porter was taken prisoner. He was released later and when Porter County was named after him in 1836, he was serving as American charge d'affairs at Constantinople. Commodore Porter died in 1843.