John White Alexander (1856-1915) was born in Allegheny City, Pennsylvania. He was orphaned at age five and taken in by relatives of limited means. When Alexander left school and began working at a telegraph company, the company's vice-president, former civil war Colonel Edward Jay Allen, took an interest in his welfare.
Allen became his legal guardian, brought him into the Allen household, and saw that he finished Pittsburgh High School.
At eighteen, he moved to New York City and was hired by Harper and Brothers as an office boy in the art department.
He was soon promoted to apprentice illustrator under staff artists such as Edwin A. Abbey and Charles Reinhart.
During his time at Harpers, Alexander was sent out on assignment to illustrate events such as the Philadelphia Centennial celebration in 1876 and the Pittsburgh Railroad Strike in 1877, which erupted in violence.