July 4th, 1776 - The proclamation of Independence from Britain was signed
1777 - The Articles of Confederation were ratified
1787 - The Constitution of the United States was written and signed
1788 - The Constitution was ratified, becoming official law
1791 - The Bill of Rights was officially added to the Constitution
1865 - The 13th amendment was ratified, ending slavery in the United States.
1870 - The 15th Amendment was passed, guaranteeing voting rights no matter what race
1920 - Women were given the right to vote by the 19th Amendment
1940 - A law to create a holiday called "I Am An American Day" was passed in congress and approved by Franklin D, Roosevelt. They hoped to encourage new citizens and voters to learn their responsibilities as citizens. At the time, the voting age was 21, so 21 year-old citizens were encouraged to learn their role in democracy. Part of this was education based on the Constitution in order to build a foundation for their understanding of Democracy. This was to be celebrated every 3rd Sunday in May.
1952 - The resolution establishing I Am An American Day was repealed so that it could be replaced with Citizenship Day. Citizenship Day was decided to occur on September 17th every year on the anniversary of the signing of the constitution. President Truman authorized these changes.
1955 - Citizenship day grew. under president Eisenhower a new holiday was created to immediately follow Citizenship day every year: Constitution Week. The hope was that a whole week would allow much more time for people to educate themselves about the Constitution and the rights it guarantees them.
1971 - The voting age was changed to 18
1998 - Citizenship Day was restructured legislatively to fit in with their new framework for national holidays.
2004 - Citizenship day was renamed Constitution Day and Citizenship Day.