The US Constitution was adopted on the 17th of September, 1787, by the Constitutional Convention in Philadelphia, Pennsylvania. Article Seven of the Constitution required that at least nine states must ratify the constitution in order for it to come into effect. The first state to ratify the Constitution was Delaware on 7th December, 1787. The ninth was New Hampshire on the 21st of June, 1788. The last of the 13 states to ratify was Rhode Island on the 29th of May 1790.
Please log in to consult the article in its entirety. If you are a member (student of staff) of a subscribing institution (see List), you should be able to access the LE on campus directly (without the need to log in), and off-campus either via the institutional log in we offer, or via your institution's remote access facilities, or by creating a personal user account with your institutional email address. If you are not a member of a subscribing institution, you will need to purchase a personal subscription. For more information on how to subscribe as an individual user, please see under Individual Subcriptions.