Ratified on February 3, 1913, the Sixteenth Amendment (Amendment XVI) to the United States Constitution allows the Congress to impose a federal income tax.This allows the federal government to collect a tax on personal income, no matter where that income came from.[a] The Sixteenth Amendment overturned the 1895 Supreme Court landmark decision in Pollock v. Farmers' Loan & Trust Co.In Pollock, the Court ruled that a 2 percent tax on incomes over $4,000 was unconstitutional. This was because the law the ruling struck down did not allow for apportionment,[b] the court ruled against it. The Sixteenth Amendment allowed Congress to levy a uniform direct income tax without being subject to apportionment. The largest and most direct effect of the passage of the Sixteenth Amendment was it shifted power from the states to the federal government.States had income taxes before the federal government did. This kept the federal government weaker due to having less revenue than the states.Without the Sixteenth Amendment, the federal government would find it far more difficult to extend its military power to other parts of the world.

Ratified on April 8, 1913, the Seventeenth Amendment (Amendment XVII) to the United States Constitution changed the method by which United States Senators were elected. For the first 125 years Article 1, section 3 of the Constitution required US Senators to be elected by the state legislatures. A number of problems in the United States Senate created the need to change how Senators were elected from indirect to direct elections by the people of the United States. The text: The Senate of the United States shall be composed of two Senators from each State, elected by the people thereof, for six years; and each Senator shall have one vote. The electors in each State shall have the qualifications requisite for electors of the most numerous branch of the State legislatures.When vacancies happen in the representation of any State in the Senate, the executive authority of such State shall issue writs of election to fill such vacancies: Provided, That the legislature of any State may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.This amendment shall not be so construed as to affect the election or term of any Senator chosen before it becomes valid as part of the Constitution.

Ratified on January 16, 1919 and went into effect a year later, the Eighteenth Amendment (Amendment XVIII) of the United States Constitution banned the making, transporting, and sale of alcoholic beverages in the United States.The Volstead Act was passed by Congress to enforce the Eighteenth Amendment. It did not prohibit the drinking of alcohol however. It started the period in American history called the Prohibition Era. This was a period of mass civil disobedience to the law. Those who could afford the higher prices of smuggled liquor went to illegal bars called speakeasies. Working class people tended to drink moonshine and so-called bathtub gin at home.The Eighteenth Amendment proved to be a major failure. Americans started drinking more than before and it caused crime to rise significantly. The Eighteenth Amendment was later repealed by the Twenty-first Amendment.It remains the only amendment to be repealed by another amendment to the Constitution. The first clause, section one, says the law was to go into effect one year from its ratification. It was passed by Congress on December 18, 1917.The thirty-sixth state (required number for passage) to ratify the amendment did so 394 days later on January 16, 1919. The forty-seventh state to ratify the amendment was New Jersey on March 9, 1922. Rhode Island was the only state to reject ratification of the 18th Amendment.The second clause gave the federal and state governments concurrent powers to enforce the amendment.Congress passed the national Prohibition Enforcement Act, also known as the Volstead Act. The act defined any beverage containing more than one-half of one percent an intoxicating beverage. It gave the Internal Revenue Service the power to enforce the law.The third clause gave seven years as the time period for the states to ratify the amendment. This is the first amendment to have a limit on the time in which it was to be ratified. If it was not ratified by the required number of states in that time period, the amendment would not go into effect.[6] Article Five of the United States Constitution requires an amendment be passed by three-quarters of the states.

Ratified on August 18, 1920, Nineteenth Amendment (Amendment XIX) to the United States Constitution granted American women the right to vote.The amendment marked the end of a long struggle for women in the United States that began in the mid-nineteenth century. The movement, called women's suffrage, marked a radical change in how women were viewed in America. When the Constitution was written, it was accepted that a woman did not have a separate legal identity from her husband. Women's suffrage challenged that concept. The Nineteenth Amendment overturned an earlier decision by the United States Supreme Court in Minor v. Happersett.The Court held that the right to vote, guaranteed by the Fourteenth Amendment to all citizens of the United States, did not apply to women.Women were citizens, but did not have the right to vote. The Nineteenth Amendment was first introduced in Congress in 1878 by Senator Aaron A. Sargent. The bill calling for the amendment was introduced unsuccessfully every year for the next 40 years. Finally, in 1919, Congress approved the amendment and submitted it to the states for ratification. A year later Tennessee gave the final vote needed to add the amendment to the Constitution.