Well, he’s right that there were no Muslims who signed the Declaration of Independence or the Constitution. There were a few Muslims who fought in the American Revolution…escaped or freed slaves for the most part. For instance, Peter Salem, the soldier at the Battle of Bunker Hill who is credited with shooting the British Marine commander Major Pitcairn was possibly Muslim. We know of a few more…Joseph Benhaley, Bampett Muhammed, and Francis and Joseph Saba were all enlisted men in either the Continental Army or the colonial militia.
There was a slave in Georgia named Bilali Mohammed who participated in the War of 1812. Interestingly enough, when he died, he had in his possession one of the earliest recorded Muslim legal documents in America…a thirteen page treatise in Arabic on Muslim law.
Regarding the Civil War, there were some Muslim Civil War soldiers; for instance a man named Max Hassan, an immigrant from Africa who served as a porter in the Union army. There was also a guy named Muhammed Said, a freed slave who fought in the 55th Massachusetts Colored Regiment.
There was also, even though he might not count, Hi Jolly (Hajji Ali), who was a Bedouin from Jordan/Syria, who was brought over in the 1850s to manage the US Army Camel Corps, which was an attempt to use camels as mounts in the American Southwest. It failed utterly and he got involved in a bunch of other failed businesses, before signing back on as an army scout during the suppression of Geronimo and the Apaches.
And, more generally, there were Muslim slaves, Muslim slave holders and Muslim slave traffickers.
Regarding Muslim roles in the Civil Rights movement, there was of course, the quasi-Muslim Nation of Islam, and the Black Panthers, many of whom were Muslim. But most of the non-black Muslim community started coming here between the 1950s-70s, and were, as one might expect, more concerned with their own advancement than with social activism.
The guy who met with Adolf Hitler was the Grand Mufti of Jerusalem, not the “Muslim Grand Mufti”, and he was pretty much an anti-Semitic Fascist, and there were some Muslim units in the Bosnian SS, as well as pro-Nazi groups in the Middle East who were hoping for a German victory to kick out the British, like, in addition to the Grand Mufti, Rashad Ali, the Prime Minister of Iraq after his coup in 1941, but I don’t know if that reflects on the Muslim community as a whole.