Rev. William Harris was born on December 20, 1831, in Chester County, Pennsylvania.

He was a clergyman. He graduated from the University of Pennsylvania in 1850. For over eight years he was engaged in mercantile business first in Philadelphia, and then in New York. In 1858, under the influence of strong religious convictions, he turned away from the business prospects and entered Princeton Seminary, graduating in 1861. He served as a Civil War Union Army Chaplain of the 106th Pennsylvania Volunteer Infantry (1861-1862) and as a Relief Agent of the U. S. Sanitary Commission (1863). He was assistant pastor of the First Presbyterian Church of Towanda, Pa. (1864-1865) and was ordained an evangelist by the Presbytery of Susquehanna in 1864. In 1870, he accepted the office of Treasurer of the College of New Jersey. Besides preaching in the college chapel, he was interested in all that concerned the religious welfare of the students. He was also the Treasurer of the Alumni Association of Princeton Seminary.

In 1864, he married Christina Van Alen Butler (1837–1918). He died on March 23, 1885, in Savannah, Georgia, and is buried in Princeton Cemetery, New Jersey.