The Sierra Club, with over 700,000 members nationwide, is the oldest grassroots environmental organization in the United States. It sees its purpose as preservation, protection, and enhancement of the natural environment.
Article IV, Section 4. This section is called the Guarantee Clause, because by its terms the federal government makes certain guarantees to the states. One of theseâprotection from foreign invasionâcontinued Congress's prior obligation under the Articles of Confederation.
How to Amend the Constitution. Article V of the United States Constitution provides authority and instructions for amending the Constitution. Amendments can be proposed by Congress or by constitutional convention. Congress then decides how to ratify the amendment if approved by Congress or convention.