Has section 740 been invoked before

Section 740 of the D.C. Home Rule Act grants the President of the United States the authority to take control of the District of Columbia's Metropolitan Police Department under conditions deemed to be of an "emergency nature." There is no strict legal definition of what constitutes an emergency under this section, leaving it largely to the president's discretion. Once invoked, the president must notify Congress within 48 hours with an explanation and justification. The federal control can last up to 30 days unless Congress terminates or extends it, with the president having veto power over congressional decisions.

According to multiple sources, including social media posts and news commentary from 2023, President Donald Trump invoked Section 740 for the first time in history. This invocation was described as unprecedented and a significant exercise of emergency powers over D.C.'s police force. Prior to this event, Section 740 had never been used.

It is important to note that other references to "Section 740" in New York Labor Law or federal regulations (such as 15 CFR Part 740) are unrelated to this specific emergency power statute and pertain to whistleblower protections or export license exceptions respectively.

Therefore, based on available information, Section 740 of the D.C. Home Rule Act has been invoked only once before, by President Trump, making it a historically unique event.