Many of his completed oil paintings of American Indian life and the Rocky Mountains originally hung in Murthly Castle, though they have now been dispersed to a number of private and public collections.

The so-called "pleasure trip" ended in a dispute that split the party and caused Stewart to return to Scotland earlier than he had planned.

By a servant girl named Christina Marie Battersby he had an illegitimate son, William George Drummond Stewart, born in 1831.

The younger Stewart had an illustrious career in the British Army and was awarded the Victoria Cross for his actions in relieving the Siege of Lucknow during the Indian Mutiny.

Here Stewart met the mountain men Jim Bridger and Thomas Fitzpatrick, as well as Benjamin Bonneville, who was leading a governmental expedition in the area.

With some of the men, Stewart visited the Big Horn Mountains, wintered at Taos, and attended the next rendezvous at Ham's Fork of the Green River.

Finding that his finances were curtailed because his brother had failed to forward his share of the estate left by their father, Stewart went to New Orleans, speculated in cotton to recoup, and wintered in Cuba.

Because Clement was restless and unhappy in Scotland, the couple spent many months travelling abroad, including an extended visit to the Middle East.

When attempts to earn extra income by hosting hunting parties proved disappointing, Stewart finally sold one the family's estates, Logiealmond Castle.

The sale provided him with enough money to pay off his brother's debts and to allow him to return to the United States for an extended, lavish party held in the Rockies.

Stewart had planned to spend the winter of 1843–1844 in New Orleans, and visit Taos and Santa Fe the following spring, but the Renaissance pleasure trip ended in a "scandal"[further explanation needed] that led him to leave for Scotland immediately, never to return to the United States.