Obama transferred to CC from Occidental College which (poor place) is rarely mentioned by the young senator. Obama also tends to forget/ignore his Columbia affiliation, preferring to mention the fact he attended Harvard's law school.
While at Columbia, he lived off campus. He claims to have spent his first night sleeping in an alley near the corner of 109th and Amsterdam Avenue and washing with the homeless next to an open fire hydrant. When he was on campus, he spent most of his time in Butler Library, and made few friends.
He majored in PoliSci, and claims to have concentrated in "International Relations," a designation which does not exist at Columbia. He wrote his senior thesis on Soviet nuclear disarmament. Obama's professors confirm that he was a brilliant, standout student and that he was an active participant in seminars. Despite this, he continually declines requests to release his transcript.
After graduating, Obama hoped to become a community organizer, but could not get a job as one. He went to work for a small consulting firm instead. In his memoir, he portrays this as a big corporate job, and claims it prompted fears he was becoming a sellout.