Chairman: Tim KaineThe Democratic Party is the oldest continuous party in the United States, and remains among the oldest in the world. Most relate the current party to the Demcratic-Republican Party of Thomas Jefferson (formally called Republicans), that was founded by Jefferson, future President James Madison and other top leaders of the era.
At the time, it's main opposition was the Federalist Party, a party held by the likes of Alexander Hamilton, John Adams, and was normally sided with George Washington, who held no political party. Although intially in the minority at the start of the United States goverment, the Democratic-Republicans quickly took control of both houses of congress in 1801 and later would also dominate the presidency.
The party changed dramically over the next twenty years as Andrew Jackson took the helm. As a result of his positions on slavery, immigration, and the national bank, a new opposing party was created called the Whig Party. Depite many presidents and big wins for the the party, Democrats dominated the polical spectrum until the Republican party was formed as a remenat of remaining whigs and a certain wing of Democrats.
Over the next 150 years, the party has been up and down. Some of the famous Democratic presidents of the modern party include Franklin Roosevelt, John Kennedy, Bill Clinton, and recently Barack Obama, the first African-American president. As of 2008, the Democrats hold signifigant control in the house, senate, and now even the presidency, a far cry from just 4 years ago.