At 6 foot 4 inches, Abraham Lincoln remains the tallest president in U.S. history. And one of his iconic stovetop hats - the one he wore (which was 7 to 8 inches tall) to Ford’s Theatre the night of his assassination - is a permanent piece of the Smithsonian collection. <br><br> Abraham Lincoln is often ranked as one of the United States’s most important presidents for his role in steering the country through the Civil War and his insistence on abolishing slavery, culminating in the Emancipation Proclamation.