What the heck was the Logan Act?

An old American law has suddenly been thrust into the news. When 47 U.S. Senators signed a letter to the government of Iran, the Logan Act of 1799 was unpacked all over again. So what is this Logan Act, and who was Logan?

The law makes it illegal for any citizen of the U.S. to “directly or indirectly” commence or carry on “any correspondence or intercourse with any foreign government or agent thereof” without the permission of the U.S. government. It is, in short, illegal to “defeat the measures of the United States”—a rather ambiguous statement, to be sure. Violations are punishable by fine and up to three years imprisonment.

It is named not after its sponsor but rather its initial target, the Pennsylvania Quaker George Logan, who in 1798 engaged in some personal diplomacy with France during the undeclared quasi-war. The party in power, the Federalists, heaped calumny on Logan, calling him, among other things, a “propagandist of sedition and philosophy.” Frederick B. Tolles does a historian’s job of rescuing Logan from his enemies in his nuanced article from 1950, published soon after the Act had one of its periodic eruptions into the politics of the day. Logan himself was never prosecuted; he went on to serve as a U.S. Senator from 1800-1806. ...