We the people : the American people and their government / [text, Division of Political History]. (OCLC #1288911)
In a SuDoc classification number, the cutter for the title is based on the first significant word in the title that denotes the subject of the resource, also excluding “catch phrases”. For this resource, “We the people” is skipped, and the cutter is based on the word American:
SI 1.2:Am 1/2
More about cuttering in SuDoc can be found in the GPO Classification Manual.