Both his and his father's names honor Revolutionary war lawyer and merchant Rawleigh Colston (1749-1823) who traded in the West Indies for military supplies for the Continental Army, corresponded with George Washington, married into the Marshall family of Virginia and bought part of the Northern Neck Propriety, which after litigation led to the family's establishment in western Virginia.

His "rigidly pious" uncle repeatedly tried to get Colston to enter the Presbyterian ministry, but the young man preferred a military career.

[4] Professor Colston and a group of VMI cadets served as guards during the November 1859 execution of abolitionist firebrand John Brown following his unsuccessful raid on Harper's Ferry.

Colston commanded the Confederate district across from Newport News during the historic 1862 battle between the USS Monitor and CSS Virginia.

[6] However, on May 3, "Raleigh Colston, the least experienced of Lee's generals of division, proved painfully slow in directing his men into action.

In November 1863, his cousin Raleigh T. Colston, an 1850 VMI graduate who had become colonel of the 2nd Virginia Infantry (also part of the Stonewall Brigade), became one of the few fatalities of the Battle of Mine Run.

Colston, "a gentleman and slow to believe evil about his fellow man"[11] got along well with most of the other American expatriates serving the khedive, such as his superiors Charles Pomeroy Stone and William W. Loring.

[12] The Khedive sent Colston to lead a small expedition to discover a route for a railroad linking the Red Sea with the Nile River.

After joining another American-led party at Berenice and surveying the harbor, they set off for Berber, Sudan in January 1874, reaching there in March.

He fell ill in March, but unlike his American second-in-command who returned to Cairo, Colston determined to press on due to his "soldier's pride.