1) The word "mountain" contains three vowels: O, U, and A.

2) The Civil Rights Act of 1964 in the United States outlawed discrimination based on race, color, religion, sex, or national origin.

3) The concept of separation of powers, as articulated by French philosopher Montesquieu, refers to the division of government responsibilities into distinct branches, such as the executive, legislative, and judicial, to prevent concentration of power.

4) The American Civil Rights Movement, led by figures like Martin Luther King Jr., fought for equal rights and helped bring about significant social and legislative changes.