Bet you didn't know that this is in the Star Spangled Banner. Not the part we sing at the baseball game, of course, but it is there, in the third stanza:
"No refuge could save the hireling and slave
From the terror of flight or the gloom of the grave,
And the star-spangled banner in triumph doth wave
O'er the land of the free and the home of the brave."
The "flight" in the lyrics refers to slaves who tried to flee the United States in order to escape from slavery. The grave, I guess was the alternative offered in the song, to freedom in another country.
Land of the Free, Hooray!!!