In Westminster-style parliaments, leaving the House or leaving the Senate is a similar concept to the need for unanimous approval. If a member asks permission to do something different from the rules, a single objection can thwart the request.   Unanimous consent agreements put land trade in order and structure and expedite legal remedies. They can be as simple as asking for a quorum, or as complicated as a binding treaty resulting from a long and often lively debate. Senators have been conducting routine business by unanimous consensus since 1789, but the UC`s more formal agreement dates back to the 1840s, when Senator William Allen of Ohio was looking for a method to end debate. In criminal jury trials, many jurisdictions require a jury verdict to be unanimous. This is not the case in civil jury trials. The unanimous adjective comes from the similar Latin word unanimus, which means “one spirit.” So if people think unanimously, they all have the same idea in mind. A vote is unanimous if all voters agree. Marcus Cicero said, “Great is power, great is the authority of a Senate that is unanimous in its opinions.” On April 13, 1846 Allen spoke again.
A vote on the Oregon issue was inevitable, he argued, so why not “accept the same day the Senate votes.” Such a measure would be acceptable, argued James Morehead of Kentucky, “provided it is not a precedent.” But it set a precedent. Senators reached a consensus and unanimously agreed to end the debate and call a vote. In June, the Senate approved treaty resolutions, a territory was established, and in 1859 Oregon became our 33rd state. Scientists believe this is the first example of the Senate adopting a formal UC agreement. Unanimous consent can be used in a consensus decision-making process. Unanimous approval in this process does not necessarily mean unanimous approval (see consensus decision § Agreement vs. . . .