April 13, 2011 - Announces that he has formed a presidential exploratory committee, but does not publicly declare his candidacy.
May 5, 2011 - Fox News ends association with Santorum and Newt Gingrich after neither respond by the May 1 deadline regarding their decisions on seeking the 2012 Republican presidential nomination.
June 6, 2011 - Launches his presidential campaign in Somerset County, Pennsylvania.
February 15, 2012 - Releases his last 4 years of tax returns showing he earned more than $3.6 million.
April 10, 2012 - Suspends his presidential campaign.