Cassilly C. Adams was born on in 1843 in Zanesville, Ohio and he was the son of William Apthorp Adams, a lawyer. He was a direct descendent of President John Adams of whom his father traced their ancestry back to. Interestingly, the elder Adams was an amateur artist so it was not surprising that at an early age, young Cassilly Adams was also interested in art.

His schooling consisted of the Boston Academy of Art and the Cincinnati Art School. It was after his education that he joined the Union army during the Civil War and when he was wounded in the Battle of Vicksburg, it was then that he produced his masterpiece, "Custer's Last Fight" which took one year to complete. As models, Adams used actual Sioux Indians in battle dress and cavalrymen in uniforms of the period. This painting was considered a vital document of American history and was exhibited across the country. The painting was eventually acquired by the Anheuser-Busch Company and was at the time valued at $10,000. The brewery ended up giving the painting to the 7th Cavalry, and it was destroyed in a fire at Fort Bliss, Texas in 1946 although a lithograph had been made of it and many reproductions.

Following the success of this painting, Adams began to concentrate on paintings depicting the American West. He gained further recognition for his compelling portrayals of the Cheyenne, Sioux and Plains Indians. His artwork is now kept in important collections throughout the United States, including the Amon Carter Museum in Texas, the Joslyn Art Museum in Nebraska, the Shelburne Museum in Vermont, and the Arizona Historical Society.

Despite his fame from the painting, "Custer's Last Fight", Adams remained a relatively unknown artist, and was considered a victim of circumstance. Most of his illustrations were done for book publishers who did not credit him with the work. Many of his illustrations were borrowed for other books and were not attributed to him. In actuality , he painted many scenes of frontier life, and it is known that he illustrated "Conquering the Wilderness" by Frank Triplett, which was published in 1883. After a long art career, Adams died at Trader's Point near Indianapolis, Indiana in 1921. Enjoy some of his paintings below.