At this time reports came of rich lead mines in upper Louisiana (now in Missouri)  which attracted the attention of Moses Austin The territory then being under the dominion of Spain  he procured a passport from the Spanish minister to the United States in 1797 and visited that region  and secured from the governor  Baron de Carondelet  a grant of a league of land covering the site where the town of Potosi  Washington County  Missouri  now is  and in  removed there with his family and formed the first American settlement in that section