The Electoral College was established in the Constitution of the United States to elect the president and vice president of the United States. During the 1787 Constitutional Convention, this system was devised as a compromise between the two ideas of a vote in Congress electing the president and a democratic popular vote by citizens electing the President. Under the Electoral College system, voters who cast their votes in a presidential election are actually voting for electors who will pledge to vote for a specific candidate when the Electoral College convenes to elect the president and vice president.
The National Archives' site on the Electoral College includes information about how the Electoral College was created and its history, the Electoral College process, how electors are selected, and other frequently asked questions. They also have historical Electoral College results.
USA.gov provides information on the presidential election process and the Electoral College.
270towin.com features an interactive Electoral College map.
Part of the American Presidency Project from the University of California at Santa Barbara, this site includes maps and voting data from 1789-2016.
The Electoral College has 538 electors. To elect the president, a majority of 270 electoral votes is needed. Each state has the same number of electors as it does members in Congress, including one for each member of the House of Representatives and two Senators. The District of Columbia also has three electors. Potential electors for each state are typically chosen by political parties to represent their candidate on the ballot. When citizens of a state vote for president and vice president, they vote to select their state’s electors. The winning candidate’s electors are appointed to serve as their state’s electors and vote for the president and the vice president in the Electoral College. The candidate that wins in a state receives all of its Electoral College votes, except in Maine and Nebraska, which awards its Electoral College votes proportionally. It is possible for an elector to vote for a different candidate than the one they are pledged to vote for, which is known as a faithless elector. However, this is very rare.
The Electoral College: How It Works in Contemporary Presidential Elections by Thomas H. Neale from the Congressional Research Service provides interesting information on how the Electoral College functions.
Opponents of the Electoral College argue that the current Electoral College process does not accurately reflect the will of the people. Some claim that the current distribution of electors overrepresents the vote of people who reside in rural states. Further, as almost all states award all of their Electoral College votes to the person who wins the majority of the popular vote in their state, it is nearly impossible for third-party or independent candidates to receive Electoral College votes, which reinforces the two-party system. Supporters of the Electoral College claim that the system maintains the relevancy of smaller states and protects their interests from getting drowned out by more populous states.
The elections of 1824, 1876, 1888, 2000, and 2016 all ended with an Electoral College winner who did not win the popular vote, which some point to as a reason for abolishing the Electoral College. Over the years, a number of proposals have been put forth to reform or abolish the Electoral College. However, as the Electoral College is established by the Constitution, a Constitutional amendment would be necessary to alter the process.