Since 1861, in the United States, seditious conspiracy is codified at 18 U.S.C. § 2384:
If two or more persons in any State or Territory, or in any place subject to the jurisdiction of the United States, conspire to overthrow, put down, or to destroy by force the Government of the United States, or to levy war against them, or to oppose by force the authority thereof, or by force to prevent, hinder, or delay the execution of any law of the United States, or by force to seize, take, or possess any property of the United States contrary to the authority thereof, they shall each be fined or imprisoned not more than 20 years, or both.
When the second branch of the federal government organizes a mob to lay siege to the first branch to interrupt the peaceful transition of elected power, that’s a seditious conspiracy.