Early treaties

As first war chief, Piomingo often visited other tribes in the southeastern woodlands, negotiating boundaries and disputes as needed. As a diplomat to the United States, Piomingo tended to favor an alliance with the new country as opposed to doing so with the Spanish—who at the time were actively courting the Chickasaw tribes to ally with them. His opponent in the Chickasaw tribes, Wolf's Friend (Ugulayacabe), along with most of the other chiefs, preferred the Spanish offers, and also made a pact with them.^[6] Both factions, however, continued their disfavor with the British, who were allied with their enemy, the Muscogee-Creeks.^[1][6]

Piomingo's interest in friendship with the United States government dates back to the early 1780s when Piomingo, following the January 11, 1781, Chickasaw attack on the Cumberland district,^{[lower-alpha 4]} negotiated a treaty of peace and friendship between the Chickasaw and the state of Virginia. This treaty was signed with Col. James Robertson on behalf of the colonists at French Lick.^{[7][8][lower-alpha 5]} Piomingo and Mingo-houma^{[lower-alpha 6]} represented the Chickasaw in November 1783, signing a treaty that gave up a large parcel of land at the juncture of Illinois, Kentucky, and Tennessee in exchange for U.S. help to evict a squatting tribe of Delaware Indians below Muscle Shoals that then would be set aside for the federal government's use, at a price.^{[3][7][lower-alpha 7]} Mingo-Houma at that time considered himself to be the war chief of all Chickasaws.^[3]

Friendship with Washington

Piomingo strove to become closer to the expanding United States and its technological advances, sometimes to the detriment of relationships with other Chickasaw chiefs and allied Native American tribes such as the Choctaw and Cherokee.^[5][9] John Quincy Adams observed this during Piomingo's diplomatic visit with Washington, and recorded in his diary that:

"...the two leaders sat together and shared 'a large East Indian pipe' that Washington had arranged to have..." –John Q. Adams^{[4][lower-alpha 8]}

Piomingo developed and cultivated a friendship with President George Washington.^[6] Letters, written by Washington, recognized his importance to the United States and its continued expansion west, as the Spanish actively sought rights to the Chickasaw lands, and had split the Chickasaw tribes loyalties in half. Creek leader, Alexander McGillivray, who with Spanish help was trying to build a pan-Indian confederation to confront America, thought him a traitor to all Native Americans.^[3]

Major treaty signer and ally

Along with Lotapaia and head white chief, Taski Etoka, Piomingo signed the Treaty at Hopewell plantation in South Carolina in January 1786.^[8] The treaty pledged both parties to peace and everlasting friendship. It also set and formalized the Chickasaw boundaries with the United States.^[5][9] Piominko, who became head war chief of the Chickasaw while at the signing when news of Red King's death reached him, never wavered from his decision to align his tribe to the U.S., even though the Federal government didn’t always live up to its side of the deal.^[4][8]

In a letter to President Washington dated October 30, 1789, Piomingo implores the government to help re-supply his tribe with bullets and gun powder to help him prepare for possible hostilities as escalating tensions with the Creek^{[lower-alpha 9]} caused him concern with expected military confrontations following the next Spring thaw.^[8] In 1792—at Washington's behest—Piomingo received a Peace Medal from Secretary of War Henry Knox for his tribe's friendship with the United States.^[5][6]