A railway survey artist, photographer and special artist for "Harper's Weekly" and the "Philadelphia Press," Major Calhoun was a member of the Union Pacific survey party led by General Wright and Dr. William Bell through Arizona, New Mexico, and Colorado in the 1860s.

He contributed articles that were published in those publications, and in 1867, an illustration of a battle and view of Fort Wallace in Kansas territory was published by Harper's from his sketches (showing 500 of 1288 characters).