There are many ways to discuss the political geography of the Americas.
First, we can simply say that the Americas are split up into many different countries. There are three countries in North America, seven countries in Central America, and thirteen in South America. There are also a number of countries in the Caribbean, the number of which is somewhat dependent on how you define a country.
Second, we can say that the countries of the Americas can be differentiated by the level of their commitment to democracy. In this view, there would be countries like the US and Canada on one end of the spectrum with their strong democracies. There would then be countries like Cuba and Venezuela on the other side. In between would be the other countries with their varying levels of democracy.
Finally, we could say that countries of the Americas can be differentiated on the basis of their relationships with one another. For example, we could split them up into different economic spheres. There is NAFTA, which binds the three countries of North America together. There is MERCOSUR, which creates an economic union of sorts between six countries of South America.
These are not the only ways to describe the political geography of the Americas, but these are three important aspects of political geography that should be considered.