Islamic history that they don't teach at Harvard:
When American colonists rebelled against British rule in 1776, American merchant ships lost British Royal Navy protection. With no American Navy for protection, American ships were attacked and their Christian crews enslaved by Muslim pirates operating under the control of the "Dey of Algiers"--an Islamist warlord ruling Algeria.
In 1786, Jefferson, then the American ambassador to France, and Adams, then the American ambassador to Britain, met in London with Sidi Haji Abdul Rahman Adja, the "Dey of Algiers" ambassador to Britain.
During the meeting Jefferson and Adams asked the Dey's ambassador why Muslims held so much hostility towards America, a nation with which they had no previous contacts.
The two future presidents reported that Ambassador Sidi Haji Abdul Rahman Adja had answered that Islam: "was founded on the Laws of their Prophet, that it was written in their Quran, that all nations who should not have acknowledged their authority were sinners, that it was their right and duty to make war upon them wherever they could be found, and to make slaves of all they could take as prisoners, and that every Muslim who should be slain in Battle was sure to go to Paradise."
In 1805, American Marines marched across the desert from Egypt into Tripolitania, forcing the surrender of Tripoli and the freeing of all American slaves.