Daniel Clark, an Irish immigrant became a rich power player in early Louisiana history. He was the American Counsel in New Orleans when it (Louisiana) was under Spanish control. Daniel Clark was the first representative from Louisiana to Congress and was instrumental in the Louisiana Purchase. Here is a letter to Thomas Jefferson from Daniel Clark regarding conditions in Louisiana.
One of Clark's business partners was James Wilkinson, who originally conspired with Aaron Burr and then turned on Burr. Clark wrote a blistering condemnation of Wilkinson. (See account of Burr's trial). What General Wilkinson wrote about Daniel Clark can be found here.
Mr. Clark is also remembered as the father of Myra Clark, the famous litigant. A summary of Daniel Clark's real estate enumerated in Myra's lawsuit can be found here.