This starts out as a history of the oil drilling industry, beginning with a prospector mining for silver in the Sierra Nevada, and then proceeds oil drilling in California the early 1900's. The main character, Daniel Plainview, travels with his orphaned boy, and dupes the inhabitants of a desert town called Little Boston. It gradually changes from a history of the industry into a character study of Plainview, as he becomes more and more wealthy and more and more of a ruthless, egocentric asshole.
I doubt anyone will like the ending. It is based on a Sinclair Lewis novel, "Oil".
The acting is excellent, but I found the plot disappointing.