In the excerpt above, George's "free soil" is a reference to his grave.
This excerpt in from Uncle Tom's Cabin
Uncle Tom's Cabin is an anti-slavery novel written by American author Harriet Beecher Stowe. The book and the plays it inspired helped popularize a number of stereotypes about black people. The book starts with a Kentucky farmer named Arthur Shelby facing the loss of his farm because of debts.
Twain likely made Henry Adams an American in England to show how far removed he was from what was viewed as proper English society. As an American he would be considered a backwards outsider that could not possibly fit in. That all changes when he receives the bank-note and then can afford to buy his way into the English society.
