Petitions from various classes of settlers, not provided for by the acts of June 20, August 28, and August 29, 1788, led Congress to pass the act of March 3, 1791. By this act, four hundred acres was to be given to each head of a family who, in 1783, was resident in the Illinois country or at Vincennes, and who had since moved from the one to the other. The same donation was to be made to all persons who had moved away, if they should return within five years. Such persons should also have confirmed to them the land they originally held. This was intended to bring back persons who had gone to the Spanish side of the Mississippi. Grants previously made by courts having no authority should be confirmed to persons who had made improvements, to an extent not exceeding four hundred acres to any one person. As these lands had in some cases been repeatedly sold, the parties making the improvements were frequently guiltless of any knowledge of fraud. The Cahokia commons were confirmed to that village. One hundred acres was to be granted to each militiaman enrolled on August 1, 1790, and who had received no other grant.(150) This act throws considerable light on the causes of discontent then prevailing among the settlers and on the conditions to which immigrants came.
This same spring, about two hundred and fifty of the inhabitants of Vincennes had gone to settle at New Madrid.(151) It is not strange that the act of March 3, 1791, made provisions intended to induce the Americans who had emigrated to the Spanish possessions to return. The history of the threatened Spanish aggression upon the western part of the United States is known in essence to anyone who has made the slightest special study of the period at which it was at its height. Morgan's scheme for a purchase of land in Illinois was not carried out, and he turned his attention to peopling his settlement at New Madrid. Down the Mississippi to New Orleans seemed the natural route for Illinois commerce. Slavery flourished unmolested west of the Mississippi. In 1794, Baron de Carondolet gave orders to the governor of Natchez to incite the Chickasaw Indians to expel the Americans from Fort Massac. The governor refused to obey the order, because Fort Massac had been occupied by the Americans in pursuance of a request by the Spanish representative at the capital of the United States that the president would put a stop to the proposed expedition of the French against the Spanish. The claim was advanced by Carondolet that the Americans had no right to the land on which the fort stood, but that the land belonged to the Chickasaws, who were independent allies of Spain. Two other reasons given for not obeying the order were that it would preclude the successful issue of the Spanish intrigue for the separation of Kentucky from the United States, and would hinder negotiations, then pending, for a commercial treaty between Spain and the United States.(152) Carondolet regarded the Indians as Spain's best defence against the Americans,(153) yet the whites prepared for defence, and in anticipation of the proposed French expedition of George Rogers Clark, a garrison of thirty men and an officer was placed at Ste. Genevieve, opposite Kaskaskia. Carondolet said: "This will suffice to prevent the smuggling carried on by the Americans of the settlement of Kaskaskias situated opposite, which increases daily."(154)