The United States Electoral College is the official name of the group of Presidential Electors who are chosen every four years to cast the electoral vote and thereby elect the President and Vice President of the United States. It was established by Article Two, Section One of the United States Constitution, which provides for a quadrennial election of Presidential Electors in each state. The electoral process was modified in 1804 with the ratification of the 12th Amendment and again in 1961 with the ratification of the 23rd Amendment. The Electoral College is administered at the national level by the National Archives and Records Administration via its Office of the Federal Register. The actual meetings of electors in each state are administered by state officials.
The Presidential Electors meet in their respective state capitals in December, 41 days following the election, at which time they cast their electoral votes. Thus the "electoral college" never meets as one national body. They ballot for President, then ballot for vice president. Afterward, the Electors sign a document called the Certificate of Vote which sets forth the number of votes cast for these two offices and is signed by all Electors. Multiple copies of the Certificate of Vote are signed, in order to provide multiple originals in case one is lost. One copy is sent to president of the Senate (i.e. the sitting Vice President of the United States); the certificates are placed in two special mahogany boxes where they await a joint session of the new Congress where they are opened and counted.
Candidates must receive a majority of the electoral vote to be declared the president-elect or vice-president-elect. If no candidate for President receives an absolute electoral majority 270 votes out of the 538 possible, then the new House of Representatives is required to go into session immediately to vote for President. (This would likely just occur when more than two candidates receive electoral votes, but could theoretically happen in a two-person contest, if each received exactly 269 electoral votes). In this case, the House of Representatives chooses from the three candidates who received the most electoral votes, but could not establish a majority of votes in the College. The House votes en-bloc by state for this purpose (that is, one vote per state, which is determined by the majority decision of the delegation from that state; if a state delegation is evenly split, a deadlock normally results, and that state is considered as abstaining).
This vote would be repeated if necessary until one candidate receives the votes of more than half the state delegations—at least 26 state votes, given the current number, 50, of states in the union. If no candidate for Vice President receives an absolute majority of electoral votes, then the United States Senate must do the same, with the top two vote getters for that office as candidates. The Senate votes in the normal manner in this case, not by States. It is unclear if the sitting Vice President would be entitled to cast his usual tie-breaking vote if the Senate should be evenly split on the matter. If the House of Representatives has not chosen a winner in time for the inauguration (noon on January 20), then the Constitution of the United States specifies that the new Vice President becomes Acting President until the House selects a President.
If the winner of the Vice Presidential election is not known by then either, then under the Presidential Succession Act of 1947, the Speaker of the House of Representatives would become Acting President until the House selects a President or the Senate selects a Vice President. On the one hand, the Twelfth Amendment specifies that the Senate should choose the Vice President, and it does not admit of a time limit on the selection process. On the other hand, the Twenty-Fifth Amendment allows the President to nominate a Vice President if a vacancy should occur. As of 2006, the House of Representatives has elected the President on two occasions, in 1801 and in 1825. The Senate has chosen the Vice President once, in 1837.