Thomas Jefferson founded the Democratic Party in 1792 as a congressional caucus to fight for the Bill of Rights and against the elitist Federalist Party. In 1798, the "party of the common man" was officially named the Democratic-Republican Party and in 1800 elected Jefferson as the first Democratic President of the United States. Jefferson served two distinguished terms and was followed by James Madison in 1808. Madison strengthened America's armed forces — helping reaffirm American independence by defeating the British in the War of 1812. James Monroe was elected president in 1816 and led the nation through a time commonly known as "The Era of Good Feeling" in which Democratic-Republicans served with little opposition.
John Quincy AdamsThe election of John Quincy Adams in 1824 was highly contested and led to a four-way split among Democratic-Republicans. A result of the split was the emergence of Andrew Jackson as a national leader. The war hero, generally considered — along with Jefferson — one of the founding fathers of the Democratic Party, organized his supporters to a degree unprecedented in American history. The Jacksonian Democrats created the national convention process, the party platform, and reunified the Democratic Party with Jackson's victories in 1828 and 1832. The Party held its first National Convention in 1832 and nominated President Jackson for his second term. In 1844, the National Convention simplified the Party's name to the Democratic Party.
In 1848, the National Convention established the Democratic National Committee, now the longest running political organization in the world. The Convention charged the DNC with the responsibility of promoting "the Democratic cause" between the conventions and preparing for the next convention.
William J. BryanAs the 19th Century came to a close, the American electorate changed more and more rapidly. The Democratic Party embraced the immigrants who flooded into cities and industrial centers, built a political base by bringing them into the American mainstream, and helped create the most powerful economic engine in history. Democratic Party leader William Jennings Bryan led a movement of agrarian reformers and supported the right of women's suffrage, the progressive graduated income tax and the direct election of Senators. As America entered the 20th Century, the Democratic Party became dominant in local urban politics.
In 1912, Woodrow Wilson became the first Democratic president of the 20th Century. Wilson led the country through World War I, fought for the League of Nations, established the Federal Reserve Board, and passed the first labor and child welfare laws.
http://www.democrats.org/a/party/history.html