The control of our nation by two parties is a result of the way we count votes, but there is no good reason to do things this way.
First-past-the-post voting, also called "plurality", only allows you to express your approval (a "yes" vote) for one candidate. ALL other candidates are treated the same, whether they are just as good as your top pick or are the absolute worst: They all get a "NO". If there is a second favorite you would rather have than the worst, plurality does not allow you to express this. The more good candidates there are, the worse it gets. Similar candidates in plurality voting are called spoilers because they take votes away from each other. Plurality voting is fundamentally flawed since it does not allow voters to say which candidates they think are good and which they think are bad.
Each election, between 33 and 60% of eligible voters do not even vote, in part because they know the current system is very broken and does not respect their vote for something better than either of the two mainstream parties is offering. We can achieve unity with like-minded people by using a method called Approval Voting.