Driving from Florida to Vancouver. What are some must see places along the way?

As mentioned in the title, I'm taking a road trip from Florida to Vancouver. Since I have friends and family I want to visit along the way, I'm taking I95 up the east coast to New York, and then I90 across the country to Seattle, Washington.

I already plan to stop at the Smithsonian, see Mount Rushmore, the Badlands, and possibly Yellowstone National Park.

I'm leaving on August 10th and would ideally like to be in Vancouver by August 24th. I know that doesn't leave me with a whole lot of time, but what are some other really good places for me to stop along the way?