Mary Bernelle McClellan was born November 23, 1926 in the Elijah Shanklin and Beedie Frances McClellan home, Hill Community, Coleman County, Texas. She attended Hill Elementary School, Hill Community, Coleman County, Texas from 1933 to 1940 and Mozelle High School, Mozelle, Texas from 1940 to 1944, graduating in May, 1944. As a student at Mozelle High School, Mary Bernelle McClellan played the clarinet in the high school band and participated in girls basketball and volleyball all four years in Mozelle High School.