What do I give someone for their 31st anniversary?

The city of New Orleans controlled the Mississippi River through its location; other locations for ports had been tried and had not succeeded. New Orleans was already important for shipping agricultural goods to and from the parts of the U.S. west of the Appalachian Mountains. Through Pinckney's Treaty signed with Spain on October 27, 1795, American merchants had "right of deposit" in New Orleans, meaning they could use the port to store goods for export. Americans also used this "right of deposit" to transport products such as flour, tobacco, pork, bacon, lard, feathers, cider, butter, and cheese. The treaty also recognized American rights to navigate the entire Mississippi River which had become increasingly vital to the growing trade of their western territories (Meinig 1993). In 1798, Spain revoked this treaty which greatly upset Americans. In 1801, Spanish Governor Don Juan Manuel De Salcedo took over for Governor Marquess of Casa Calvo, and the right to deposit goods from the United States was restored.