The road to the U.S. presidential ballot is long, hard, and expensive. First, you should know there isn't one ballot for the presidency -- there are 50 different ballots, one for each state. The U.S. Constitution does not specify how the president should be nominated, so it is left to the individual states to decide the process. As a result, each state has its own requirements for a candidate to make it onto its ballot.
Since the early 20th century, the two major political parties, the Democrats and the Republicans, have controlled the presidential nominations. Through primary elections held in each state, the parties select their nominees. This may be the easiest way for you to get in the election because states automatically put the Democratic and Republican candidates on the presidential ballot. Of course, you still have to work within the party to get your name on their short list.
Third-party and independent candidates have a much tougher time of it. States may require a potential candidate get a large number of voter signatures, pay steep filing fees, and follow lots of complicated procedures before he or she can get on the ballot. According to Richard Winger, publisher of the nonpartisan Ballot Access News, such a candidate may have to gather as many as 750,000 signatures and fork over filing fees of $8,100 to get on the presidential ballot in all 50 states. Even for a motivated and organized candidate, these requirements are daunting. For example, in the 2000 presidential election, the high-profile Green Party candidate, Ralph Nader, didn't make it onto the ballot in three states.
Many, but not all, states allow voters to write in a candidate's name on the ballot itself. States may limit this to just the primaries or open it to the general election. The write-in candidates are often required to register in advance and pay the same filing fees as other candidates. Also, court rulings have made it possible for more states to eliminate write-in voting completely.