Mike's Death in Office Rule For Presidential Monuments

RULE: If you, as President of the United States, die while in office, you will get a gravesite that is big and impressive. 

Examples are:

William Henry Harrison

Zachary Taylor

Abraham Lincoln

James Garfield

William McKinley

Warren Harding

and

John F. Kennedy. 

The only exception to the rule is Franklin Roosevelt. 

Conversely, only Ulysses S. Grant has a huge monument but did not die in office.