The Tea Party had its origins in 2008 (that’s right, before Obama was elected) with blogger Karl Denninger and a woman named Stephanie (I don’t know her last name). They were protesting the bank bailouts and Denninger suggested that people mail tea bags to their representatives. It didn’t get much attention at the time.
The movement really caught fire with Rick Santelli’s famous rant on CNBC in early 2009. So it had a genuine grassroots beginning, but since then national organizations like Tea Party Patriots and Tea Party Express have tried to claim leadership. The Republican Party establishment has been trying to co-opt and/or neuter the grassroots efforts.