" Fort Union was the best built post on the Missouri, and with the possible exception of Bent's fort on the Arkansas, the best in the entire West. It was 240 by 220 feet, the shorter side facing the river, and was surrounded by a palisade of square hewn pickets about a foot thick and twenty feet high. The bastions were at the southwest and northeast corners, and consisted of square houses 24 feet on a side and 30 feet high, built entirely of stone and surmounted with pyramidal roofs. There were two stories; the lower one was pierced for cannon and the upper had a balcony for better observation. The usual banquette extended around the inner wall of the fort. The entrance was large and was secured with a powerful gate which in 1837 was changed to a double gate on account of the dangerous disposition of the Indians owing to the smallpox scourge. On the opposite side of the square from the entrance was the house of the bourgeois, a well-built, commodious two-story structure, with glass windows, fire-place and other 'modern conveniences.' Around the square were the barracks for the employees, the storehouses, work shops, stables, a cut stone powder magazine capable of holding 50,000 pounds, and a reception room for the Indians. In the center of the court was a tall flag staff around which were the leathern tents of half-breeds in the service of the company. Near the flag-staff stood one or two cannon trained upon the entrance to the fort....All of the buildings were of cottonwood lumber and every thing was of an unusually elaborate character. "
Pages 959-960.