commander of the fortifications at Fort Ward near Alexandria, Virginia. Edward R. S. Canby had also been promoted to Brigadier General following the successful defense of New Mexico against the Confederate invasion and transferred to Washington, D.C., where he served as Assistant Adjutant General and military aide to Secretary of War Edwin M. Stanton. Tappan met personally with General Ulysses S. Grant and received an invitation from Grant to visit his field command at City Point, Virginia, where he spent several weeks before returning to Colorado. Tappan returned to Colorado in November 1864 and was laid up at Fort Lyon, Colorado Territory with a broken foot incurred on the eve of his arrival. This was two days before elements of the First Colorado Cavalry, together with the 100 day soldiers of the Third Colorado Cavalry, under the command of Colonel Chivington, initiated an attack on a peaceful encampment of Southern Cheyenne and Arapaho Indians at Sand Creek. The attack, involving 675 cavalry troopers, originated at daybreak on November 29, 1864, who departed from Fort Lyon at 8 pm on November 28 following an argument between Chivington and some of the officers at the fort who tried to dissuade Chivington from making the attack. There was a general understanding with the Cheyenne and Arapaho Indians encamped on Sand Creek that they were under the protection of the Federal troops at Fort Lyon pursuant to an agreement reached that Fall with the then Commander of the fort, Major Edward W. Wynkoop. It is not known if Tappan played any part in the discussions with Chivington at Fort Lyon on November 28 before the attack. The Federal troopers under Chivington's command attacked the Indian villages at first light and killed 150-200 Indians, two-thirds of whom were women and children. The Federal troops lost ten soldiers and had 38 wounded (of whom four later died while at Ft. Lyon), some of the casualties apparently arising from friendly fire and disorder among the cooperating units. Some of the victorious troopers mutilated the bodies of their Indian victims and returned to Denver where these grisly battle souvenirs were proudly and publicly displayed to the citizens of Denver. The action at Sand Creek was greeted by citizens of Denver as a justifiable military victory which helped to avenge the murders of Plains settlers such as the Hungate family. However it eventually began to be seen in the