What is the origin of the idiom "in cahoots" and when to use it?

The idiom "in cahoots" originated from the late 19th century American slang term "cahoot," which referred to a partnership or collaboration between individuals for a common purpose, often with a secretive or illicit undertone. The phrase "in cahoots" emerged from this term and is used to describe a close association or collusion between two or more people who are working together, often in a secretive or conspiratorial manner, to achieve a shared objective.