Answer: formal
The sentence comes from the Gettysburg Address, an extremely famous and popular speech given by Abraham Lincoln at Gettysburg, in order to honour those who died there. The tone is formal, as is the case with most political speeches. In the speech, Lincoln reminds people of the sacrifices of those who died for their country, and he claims that they have consecrated the land far more than the living could. He ends by hoping that the government of the people, by the people and for the people shall not perish from the Earth.
