making it as brief as i can, the commanding officer of the third regiment was a colonel named john sheivingten, abolitionist, he was a nationalist. he saw the project of preserving the union and the united states expanding in the american west as intertwined. he saw liberty and empire as moving in lockstep in the american west. and he wanted to move colorado territory towards status as a state. to enter the union. and he was an agent of an emerging american empire, and the slaughter at sand creek was part of a series of bloody engagements that in some ways flowed to sam creek and from san creek during the civil war. engagements involving federal soldiers and native peoples and after the war was over, became one element of reconstruction in the wars exploded. >> alexa, sand creek has been a national park since when? alexa: it was authorized in the year 2000, and establish in 2007. >> and it is a national park site. wasn't it president clinton who signed the legislation? alexa: yes. >> talk about the history behind the creation of the historic site? prof. roberts: it began in 1998 with the passa