You're refering to the first congress puchasing 10,000 acres of land for the "Moravian brethren" July 27, 1787 for "promoting Christianity"?
I believe that it was actually 12,000 acres.
The First U. S. Congress didn't buy the land in question and it wasn't granted to the Moravians for the purpose of promoting Christianity.
In 1787 or it might have been 1788, the Continental Congress granted a trust in some land in Ohio to a group of people who organized as “
The Society of the United Brethren for propagating the Gospel among the Heathen” for the purpose of helping a pacifistic tribe of brutalized Deleware Indians (Known as the "Christian Indians") return to land in Ohio that they had occupied, as very successful farmers, at the beginning of the American Revolution.
At the start of the Revolution, the Continental Congress had promised to give the Indians offical ownership of the land they occupied in Ohio in exchange for the Indians, who were pacifists, not taking up the hatchet against the Americans.
The Indians kept their promise. However, they had been brutalized during the war by other Indian tribes, the British and the Pennsylvania militia. By the end of the war, many of the Indians were dead and the surviors had dispersed. Eventually a group of turvivors a decendents were found in Canada.
To make a long one short, the Society failed in its attempt to convince the Indians to re-occupy the land in question. In 1823, the Moravians gave up on their noble attempt to get the Indians to take title to the land that was rightful theirs and reliquished the land back to the United States.