Michael Flynn’s Resignation Has People Talking About the Logan Act. Who Was Logan?

When President Donald Trump's National Security Adviser Michael Flynn resigned on Monday night, after admitting to speaking with Russia’s ambassador to the U.S. about sanctions in December, an obscure law was suddenly on the minds of Washington observers: the Logan Act.

The law prohibits unauthorized U.S. citizens — which Flynn was at the time — from speaking to foreign governments about that country's "disputes or controversies with the United States.