What is the first movie in the United States to have large commercial success?

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I am doing a research paper and the topic is When cinema in the early 1900s started to become a social media.

I figure the first place I should look is what the largest movie with the most success was in that time period.

If anyone has any ideas or advice on what else I should look for, it would be really appreciated. It has to be 10 pages so REALLY, any help at all would be awesome.