Assumption Parish was created from one of the original 12 counties. Assumption parish was named for the Assumption Catholic church at Plattenville, the oldest Catholic church in the state. The original church was erected in 1793, during the Spanish regime. The present building dates from 1856. The present boundaries were created in 1807 from a portion of Lafourche Parish. As is the case in most South Louisiana parishes, the early settlers were French. The earliest permanent settlements were mde by Spanish and exiled Acadians along the historic bayou Lafourche.
The parish seat of Assumption is Napoleonville. the present courthouse, in continuous use, was built in 1895. The town was incoporated on March 11, 1878, and named by a soldier who served under Napoleon Bonaparte. With an area totally 338.7 square miles, Assumption Parish has 11 public schools, 2 private schools, 16 churches, and 3 rail lines.
Chief agriculture in Assumption Parish are corn, vegetable farming, sugarcane, and beef cattle. Industry is sugarcane refining.P>Visit the Annual Spring Louisiana Heritage Tour, sponsored by the Foundation for Historical Louisiana; Madewood, a 20-room antebellum mansion built by Thomas Pugh in 1848, which sponsors the Madewood Arts Festival in the spring; Christ Church (1853), of beautiful Gothic architectural construction with handmade brick and native cypress.