The Constitution started out with only land owners being allowed to vote.
The drafting committee struggled with this question, and decided that agreement among the states was not possible, so they dropped it.
Qualifications of Suffrage (August 7, 10) & The Anti-Federalist Papers - 1786-1800
There are some very interesting remarks in that collection, especially regarding the ability of cities to run roughshod over the process, in addition to the well-known principle that the public is generally not well informed.
US Constitution, for reference.