Admission of States to the Union: A Historical Reference Guide

The Constitution allows Congress to admit “New States ... into this Union.” By ratifying the Constitution in 1787-1790, the 13 original states—which declared independence from Great Britain in 1776 and initially united under the Articles of Confederation—joined the new federal government. An additional 37 states joined between 1791 (Vermont) and 1959 (Alaska and Hawaii). Each star on the national flag represents one of the 50 states. This report provides historical information about each state’s journey to statehood with a focus on the role of Congress. A chronology describes selected events for each state such as the formation of a territorial government; federal legislation that enabled residents to prepare for statehood; the drafting and adoption of a state constitution; and federal legislation that admitted the new state into the Union. Citations point, in general, to primary legislative sources such as the Congressional Record, House Journal, and Senate Journal. The five tables in this report summarize key information across all 50 states: admission order and date, territorial law (if any), enabling law (if any), admission law, and the outcome of state-level ratification or referendum votes (if any). This report does not address the history of a territory before its acquisition by the United States, policy or legal questions related to statehood, potential future action by Congress, the status of current U.S. territories, or statehood-related proposals that have not become law.