[2] Prairie du Rocher is one of the oldest communities in the 21st century United States that was founded as a French settlement.

About four miles to the west, closer to the Mississippi River, is Fort de Chartres, site of a French military fortification and colonial headquarters established in 1720.

Surpluses from the productive cultivation by habitants later helped supply critical wheat and corn to New Orleans and other lower Louisiana Territory communities.

Every kind of grain and vegetables are produced here in the greatest abundance .... they have, also, large numbers of oxen, cows, sheep, etc., upon the prairies.

The villagers had plots for cultivation defined in typical French fashion: long narrow lots that reached back from the riverfront through the common.

They quickly created an agricultural community with characteristics similar to Prairie du Rocher.

Additionally, King George III's Royal Proclamation of 1763 designated all the land west of the Appalachians and east of the Mississippi an Indian Reserve.

Reportedly, his campaign caused some of the remaining French settlers to emigrate to the Spanish-controlled territories west of the Mississippi, leaving relatively few in Prairie du Rocher.

After levees broke to the north near the towns of Columbia and Valmeyer, Illinois, flood waters engulfed Fort de Chartres.

With only the Prairie du Rocher Creek levee protecting the town, residents discovered a unique situation had developed.

The Army Corps of Engineers (COE) decided to use a barge-mounted shovel to break through the Mississippi River levee near Fort de Chartres, to allow flood waters to escape back to the Mississippi River channel.

The village put out a call for help and added a foot and a half of sandbags to the creek levee.

Finally, the two openings allowed enough water to escape back to the main channel so that the town was saved from flooding.

[13] Another is the Creole House,[14] constructed in 1800,[15] which was built in the French Colonial style by an unknown English-speaking immigrant from the eastern United States.

According to the 2010 census, Prairie du Rocher has a total area of 0.57 square miles (1.48 km2), all land.

The volunteer fire department occupies part of the city hall (which also houses the post office).