I have always thought of soul and jazz as America's own true, homegrown art forms. I'll play some soul and jazz today in honor of that idea. Some Marvin Gaye, some Diana Ross, some John Coltrane, perhaps some OutKast.
I'm really tempted to build a small float around a garden tractor wagon, with the Grateful Dead's "Uncle Sam" standing at a podium. Then find a good DC powered chip amp, a Walkman CD player, a pair of CV speakers, then blast the song on a loop throughout the entire parade. Maybe add Woody's "This Land is Your Land" for good measure.