Every four years on the first Tuesday following the first Monday in November, Americans get to vote for the President of the United States of America and Vice President. A lot of people think that they are voting directly for the president, but they are actually voting for the party slate of Electors representing their choice for president and vice president. Whichever party slate wins the most popular votes becomes that state's Electors. So whichever president wins the most popular votes, wins all the Electors of that state. There are however two exceptions to this rule. In Maine and Nebraska the two Electors are chosen by statewide popular vote and the remainder by the popular vote within each Congressional district.
The Electoral College is a way in which the states get a voice in the election for president. States are represented by the total number of representatives in the legislative branch.
For example, a state like Kentucky has six Representatives and two Senators. So Kentucky would have eight electoral votes. (Map) In order to prevent Electors from voting only for "favorite sons" someone from their home state, at least one of their votes needs to be for a person from outside their State. This is not really a problem because the parties always nominate presidential and vice presidential candidates from different States.
The Constitutional Convention had many ideas for selecting a president. One idea they had was for the Congress to choose the president. This wasn't a good idea because people would get mad at Congress for making a bad decision. It could also lead to political corruption.
A second idea they had was for the State legislatures to select the president. This idea was also rejected " out of fears that a president so beholden to the State legislatures...