Hats, humor and protests: A look at Queen Elizabeth's 'special relationship' with Congress

She's met with nearly every U.S. president since Truman — but her 1991 joint address on the Hill was a huge moment.

Hats, humor and protests: A look at Queen Elizabeth's 'special relationship' with Congress
She's met with nearly every U.S. president since Truman — but her 1991 joint address on the Hill was a huge moment.