L. Clifford Davis, a civil rights lawyer who led efforts to desegregate high schools in Texas, sometimes in the face of mob violence, hostility from state politicians and threats on his life, died on Feb. 15 in Fort Worth. He was 100.

His daughter Karen Davis confirmed the death, in a nursing facility.

Although the U.S. Supreme Court outlawed public school segregation in 1954 in its ruling in Brown v. Board of Education of Topeka — a case on which Mr. Davis had worked alongside Thurgood…