You continue your walk a little farther. Alongside Lafayette Square, concrete posts block the side street called Jackson Place. The post nearest the park looks like it has been hit by a car or truck-the concrete has been cracked off, revealing the metal post inside.
Across Jackson Place is Blair House. It was built in around 1824 and sold to the government in 1942. Foreign officials sometimes stay here when they come to see the President. In 1950, right here on Pennsylvania Avenue, Puerto Rican nationalists staged an assassination attempt against President Harry S. Truman, who was in Blair House at the time. The gun battle on Pennsylvania Avenue left one of the would-be assassins and a White House guard dead. The President was unharmed.