How has the Geography of the United States shaped its history?

How should the student cite this source using mla citation format?

The political cartoon below was drawn by thomas nast in 1871: a political cartoon shows a heavy set man with a long nose and a beard in a suit and vest. he is smoking a cigar and has a menacing expression. he leans against a large box that says, in counting there is strength. on top of that box is a smaller container labeled, the ballot. dialogue under the cartoon reads, thats whats the matter. boss tweed, as long as i count the votes, what are you going to do about it? say? public domain what issue does this cartoon address?

The land bridge and coastal crossing theories concern the earliest human migration from