Impressment was something that was done by the British but which had a major impact on American history. Impressment was the British practice of taking private sailors from British ships or sea ports and forcing them to join the Royal Navy.
In the time after the US became independent, the British continued to impress sailors from American ships. This showed that the British continued to think that Americans were subjects of Britain. The British felt that they could treat American ships and sailors as if they were British. This practice helped to lead to the War of 1812 between the US and Britain.