The Crownsville State Hospital in Maryland, once the state’s most crowded psychiatric institution, has sat in decay for decades, a relic from the area’s painful history during segregation.

The hospital, originally called the Hospital for the Negro Insane, opened in 1911 in a rural part of Anne Arundel County, between the coastal charm of Annapolis and the suburbs of Washington. It was a time when lawmakers and health care officials claimed to see a rise in mental illness among Black Americans, which they blamed on their freedom from slavery. Treatment there was often neglect or outright abuse, said Antonia Hylton, author of the book “Madness: Race and Insanity in a Jim Crow Asylum.”

The hospital began to be desegregated in 1948, but the process was slow and it never lost its bleak reputation. In her book, Ms. Hylton, citing a Baltimore Sun article from 1949, wrote that “men and women were sleeping in basement storage rooms and in sweltering attics without fire escapes,” and that children were sometimes housed in the same area as “men who had been labeled as sex offenders.”

At its peak in the 1950s, the hospital had 2,700 patients. That number drastically declined in the second half of the 20th century as news of how they were treated became widely known and public funding for mental health treatment withered during Ronald Reagan’s presidency.