This is the grave of Ulysses S. Grant.
Ulysses S. Grant was a failure at basically everything in life up to the Civil War, rose out of obscurity and disgrace to lead the nation in the crushing of treason in defense of slavery (although Grant himself had married into a slaveholding family), became the nation’s most popular individual, served as an entirely mediocre president who was in awe of the wealthy and a sucker for the schemes of Jay Cooke that helped plunge the nation into the Panic of 1873, became a unfortunately vilified president by those who hated Reconstruction, and, in recent years, has become a wildly overrated president by those who want to reject the Dunning school of history. Ulysses S. Grant was a great general, a man with a decent but not great record on civil rights as president (he openly lamented the 15th Amendment by the end of his presidency), and has been batted around like a tennis ball by detractors and defenders. Ulysses S. Grant also liked whiskey.
Ulysses S. Grant is buried at the General Grant National Memorial, New York, New York.