What kind of laws set up segregation facilities for white and black people in the South beginning after the Civil War and continuing through the 1940s?

The laws were often called Black Codes, though in fact they often affected American Indians, Chinese people, and Mexicans as well. A later set of codes were often called Jim Crow laws. Some of the laws actually stayed in place as late as the 1970s, and de facto legal segregation continued in education into the 1980s and, by some measures, continues to this day.
There had been Slave Codes in all slave states, which typically included restrictions on where free Black citizens could live, work, whether they could go to court or vote, and who they could marry or have children with. The first Black Codes in Reconstruction now applied these laws to former slaves.
There were separate schools, public bathrooms, railroad cars and carriages (and later, buses), drinking fountains, theaters, and even graveyards. In some places, black and white people were executed separately, by hanging from different trees. The laws also required every black adult to have a contract to work or be sentenced under vagrancy or apprentice laws. The sentence was usually labor during the day (on a plantation) while being jailed at night. Since the convict's wages went to the county or state, this replicated the old conditions of slavery as closely as possible.
The first Black Codes were overturned by Congress with the first Civil Rights Act (1875) and the 14th and 15th Amendments. Once the Republican Party ceased defending civil rights after the Compromise of 1877, most Southern states passed Jim Crow laws. Some Northern and Midwestern states followed. Some states in the Southwest passed laws aimed at Mexicans, while on the West Coast, similar laws were aimed at Chinese people and, later, other Asians. The Supreme Court, the civil rights movement, and several presidents all combined to overturn these laws from the 1950s to the 1980s.