Final answer:
The cause of the Embargo Act of 1807 was the British impressment of American sailors.
Step-by-step explanation:
The cause of the Embargo Act of 1807 was the British impressment of American sailors. The British Royal Navy was seizing American sailors and forcing them into service on their warships. The incident that led to the Embargo Act was when the British warship HMS Leopard fired on the U.S. naval ship the Chesapeake and took four American sailors. President Jefferson responded to this crisis by imposing a sweeping ban on trade, hoping to pressure Britain into stopping their impressment of American sailors.