The U.S. Constitution does not discuss or describe political parties. Indeed, many of the founding fathers feared the rise of parties: They felt that partisanship could tear apart the young nation. But political parties emerged almost as soon as the new government was established. Within a few years, John Adams ran for the presidency as a Federalist in 1796 and Thomas Jefferson ran as a Democratic Republican in 1800.
Today political parties continue to greatly influence American politics: They shape elections, define political disputes, and organize Congress. Our political leaders generally come from either the Republican or Democratic Party. Nevertheless, the American political system supports more than just these two parties, and third-party candidates often have lasting impacts on the politics, even if they rarely win major races.