That's what I suspected. Landowners. That was a class.
There was actually a specific reason that the founders only allowed land owners to vote, and it had very little to do with class as we think of it today.
They recognized a danger, made plain in the classical world, that we for the most part have entirely forgotten. In classical democracies in almost every case the democracy was destroyed eventually by itself. They way almost all of them came to an end was that clever politicians figured out that if they could control the people's will they could control the state and essentially do what they want.
They also figured out that the "mob" the masses of common people are very easy to control. You simply indulge their common desires and through doing so, you can essentially shape the government according to your own will.
The desires of the common masses of people have rarely varied down through history because there is a sort of common denominator that they always devolve to. Unless there is some outside force that acts upon them to shape their desires in a different direction, they almost always revolve around comfort and entertainment.
Further, it has been the universal tendancy of virtually all peoples that they are willing to get those things at the expence of others who have them. IE those who percieve themselves as the 'have nots' are usually willing to get what they want at the expense of those they perceive to be the 'haves'
These are principles which were demonstrated numerous times in the democracies of the ancient world and they are principles that the founders of America were very familiar with.
They founded the US specifically on the idea that anyone who pays taxes has a right to be represented in the government. However, at that time, only land owners paid taxes.
Further, land owners were the only people who really had a direct stake in many of the decisions the government made, like taxation, spending policy, trade policy etc.
They further were convinced that allowing those who had less to lose in material terms a controling interest in government was a recipe for the destruction of the very freedom that they were intending to create.
It should not be believed for one moment that they therefore created a aristocracy or an oligarchy in which the rich landowners ruled for their own interests.
They founded a system, the bedrock foundation of which was the inalienable individual rights of all mankind, and equal application of the law.
Thus even if the rich landowners wanted to impose different standards on the poor, or take away the rights of the poor etc, they could not do so because the most fundamental principle of our system is that everyone is subject to the same law and everyone has the same inalienable rights.
Thus to do something negative to the poor they would have to do it to themselves as well.
Looking at it from this perspective it makes sense that you would only give the privilage of voting to those who have something tangible to lose by giving the government too much power.
The poorer people have their freedom to lose but history has shown time and again that they are often willing, or possibly simply not aware enough of the dangers involved, to give government the power to take away their freedom in exchange for temporary material gain. (usually in the form of comfort and entertainment, sometimes for 'safety').
The US is one of the few examples in history where that, by and large, has not been the case, because of our strong cultural ethic of personal liberty. However, it has become more and more true of our people as well as dependance on government has grown.
On the other hand, the best interest of land owners was to keep the government out of their business as much as possible and keep the government limited to its central tasks.
So, giving the vote to those who don't pay taxes and to those who essentially either have no direct stake, or have a more compelling personal interest than freedom, or the well being of the republic is at best dangerous, at worst a gaurentee of the collapse of the free republic.
Giving the vote to those who have a direct stake, and have their own personal interest in line with the best interests of the people as a whole (ie personal freedom and the limitation of government from undue involvement in people's private affairs) is the best way to keep the government in line and stop the ambitions of power hungry would be rulers.