The Deep South or the Lower South is a cultural and geographic subregion of the Southern United States. The term was first used to describe the states which were most economically dependent on plantations and slavery. After the American Civil War ended in 1865, the region suffered economic hardship and was a major site of racial tension during and after the Reconstruction era. Before 1945, the Deep South was often referred to as the "Cotton States" since cotton was the primary cash crop for economic production. The civil rights movement in the 1950s and 1960s helped usher in a new era, sometimes referred to as the New South. The Deep South is part of the highly-religious, socially conservative Bible Belt and is currently a Republican Party stronghold.