The concept of separation of powers in government is most prominently associated with French political philosopher Montesquieu, who articulated this framework in his work "The Spirit of the Laws" published in 1748. He proposed that government should be divided into three branches: legislative, executive, and judicial, each with distinct functions and powers. This idea aimed to prevent any one branch from becoming too powerful and to maintain a system of checks and balances. Montesquieu’s theory greatly influenced the framers of the U.S. Constitution, leading to the establishment of a similar structure in the United States government.