U.S. Constitution
The United States Constitution was created on September 17, 1787. The following annotated editions of the United States Constitution can be found online or at the Gould Law Library at:
State Constitutions
If you're looking for a State Constitution, you can often find links to the text online, for free, at the State's official website.
The Cornell Legal Information Institute (LII) also has a list of links for the laws of all fifty states. This list includes not just each state's constitution but important links for other state government websites such as the judiciary and links to court rules or state regulations.
Additionally, you can find this information on Westlaw or Lexis in the same way you would look for the US or New York State constitution.
New York Constitution
The first New York State Constitution was adopted on April 20, 1777. Since then, four subsequent Constitutions were adopted; the last in 1938 (which has been amended since then, but not replaced.) You can find the text on line at:
Constitutional History of New York
This highly valuable resource, first published in 1906, is a five volume treatise on New York State Constitutional History, authored by Charles Z. Lincoln. You will find the original text of each of the five adopted Constitutions, as well as other key documents and research resources for New York's Constitutional history. You can access this resource in print and online.
International Constitutions
The Constitute Project offers pdf downloads and online copies of many constitutions from around the world. You can find the list of countries here. Also available are datasets and further information of each constitution and its history. William S. Hein and Company, the Oxford University Press, and International IDEA, provided the majority of the information.
International materials are also available on Westlaw and Lexis although the information is not always complete. You can find international material on Lexis by clicking the tab that says International beneath the search bar. On Westlaw you can find international material by scrolling down to the specialty areas section and clicking International Materials.