Muslims have fought in all major US wars including the American Civil War, World War I, World War II, and the Vietnam War. More recently they have served in Gulf War, Iraq War, and the War in Afghanistan. There are 5,896 self-identified Muslims currently serving in the military, according to the Department of Defense.
I suppose the Muslims get their float because they earned it by fighting with the armed forces of the USA.
Perhaps the veterans who fought under the Confederate flag don’t get a float because they fought against the United States of America.
Perhaps no Confederate veterans have applied for a float because all the Confederate veterans are dead now as opposed to the 3,550 Muslim soldiers currently serving in the US army or the 1,036 Muslim sailors serving in the US Navy or the 765 Muslim Airmen currently serving in the US Airforce or the 545 Muslims serving in the US Marines who are all very much alive serving their country and protecting their fellow Americans.
Perhaps you should thank them for their service and perhaps salute their representatives as their float passes by.