Why does the United States have two party system?

Why does the United States have two party system? In your response, explain the role of Plurality/winner take all voting and its role in our Election College system. What are the trade offs (pro and con) with our two party system? If possible, illustrate your points with examples from 2016 election. Do election matter? Why or why not? If you are eligible to vote, did you register and are you going to vote? Why or why not?