I went through pictures of my Bicentennial collection looking for cars that had July 4th on them, and to my surprise only found two. Both are traditional size cars.
MTH lighted M&M boxcar
Lionel moving parade car
Here are pictures of my two MTH American Freedom Train steamers, the T-1 and the GS4. Maybe someday one of the manufacturers will make a T&P 2-10-4 and release one in #610's AFT scheme. Then I'll have all three steamers that pulled the AFT