The Constitution remained in force only until a new Partition of Poland in 1793, but its influence was profound. Professor Marek Zebrowski summarizes:
The Enlightenment Era in Poland brought an economic revival as well flourishing of arts and literature. Writers such as Hugo Kołłątaj and Stanisław Staszic postulated far-reaching political and social reforms and laid the groundwork for the Polish Constitution. The process was officially launched in 1787, when Ignacy Potocki was selected to coordinate the project. A lively constitutional debate ensued and lasted almost four years. It pitted two camps against each other—the reformists who wanted to strengthen the government and extend voting rights beyond the landed gentry, and the powerful landowning class that was loath to relinquish their cherished privileges.
The successful vote for the 1791 Constitution was a result of a carefully planned surprise, practically tantamount to a constitutional coup d’état. Most of the Sejm’s deputies were on holiday and procedural calls for a quorum were ignored. Supporters of the Constitution occupied the chambers and the public gallery, and their overwhelming presence secured a passing vote. Since saving Poland’s uncertain future was paramount in the minds of its drafters, the new Constitution was a pragmatic mixture of progressive and conservative ideas. It called for a return of the hereditary monarchy and it restricted some privileges previously granted to religious minorities. On the other hand it abolished the liberum veto law, extended legal protection to a wider sector of Poland’s citizens, and restored the right of the monarch to nominate ministers that would be responsible to the Sejm. The progressive features of the 1791 Constitution, such as the habeas corpus provision that covered all property owners and a clear statement that all power emanates from the will of the people, were clearly rooted in sixteenth-century legislation and political theories of such reformists as Andrzej Frycz-Modrzewski (1503-1572) and Wawrzyniec Goślicki. . . .
The May 1791 Constitution was translated into French, German, and English and many prominent figures, including Thomas Paine and Edmund Burke, praised Poland’s progressive thinking and democratic spirit.These objects and documents associated with the promulgation of the Constitution and the subsequent revolutionary upheavals are from the great Czartoryski Museum in Kraków. (Closed for extensive renovations for several years, it may reopen in 2018).
Extensive discussion and English translation of the Constitution from Wikipedia.