Basically, Texas has had underwater areas for as long as it has existed. When it was discovered that there were oil deposits there, the federal government wanted to take it away from Texas who was a recognize owner of the land. It was a case where the state and the federation had to fight in the supreme court. Politics changed because Texas started hating on anyone who tried to take it away so they switched their presidential support based on this.
Penn was a firm believer in treating Native Americans (relatively) well both for moral and pragmatic reasons. He believed the success of his colony depended on good relations with Native Americans. .
The main economic factors that encouraged the growth of slavery was the heavily agricultural basis of the South's economy, which relied very much on slave labor. The geographic location of the southern colonies also made tobacco growth, and thus a demand for slaves high.
