Wabasha II (c. 1773–1836), also known as Wapahasha, Wapasha, or "The Leaf," succeeded his father as head chief of the Mdewakanton Dakota tribe in the early 1800s. He led the Dakota forces fighting with the British in the War of 1812, but sided with the United States in the Black Hawk War of 1832. Chief Wabasha II signed the Treaties of Prairie du Chien in 1825 and 1830.

In 1843, the settlers of Rocque's Landing changed the name of their town to "Wabasha" in honor of the chief. A statue of Wapahasha II stands next to a fountain in present-day Wabasha, Minnesota, on the west bank of the Mississippi River.

For a time in the late 1700s, the Mdewakanton Dakota were said to have united into a large village called Titankatanni (meaning "great old village") on the lower Minnesota River, with as many as 400 lodges. By 1805, however, Titankatanni had split up due to the decline in the local population of game for hunting. The old Mantanton, Watpaton and Issati bands had dissolved, and five new Mdewakanton bands had formed and spread out geographically.

Chief Wabasha II led an offshoot of the Mantantons which called itself the Kiyuksa (Keoxa) band. In the early 1800s, the Kiyuksa band migrated periodically between the mouth of the upper Iowa River and Lake Pepin, and hunted on both sides of the upper Mississippi River. By 1830, the Kiyuksa band under Chief Wabasha grew to be over twice as large as any other Mdewakanton band.

Wabasha had kinship ties to French Canadian fur trader Joseph Rolette, who married his niece, Marguerite Dubois, in 1807. He regularly stepped in to assist Rolette when there was trouble with hunters in his band, or when Rolette's clerks faced competition. In turn, Rolette probably advised Wabasha on issues such as the War of 1812, in which they both fought for the British, and relations with the Americans.

Another prominent fur trader with kinship ties to Wabasha was Augustin Rocque, whose parents were French Canadian voyageur Joseph Rocque and one of Wabasha's sisters.

In the fall of 1805, Lieutenant Zebulon Pike stopped at the mouth of the Upper Iowa River to meet with Chief Wabasha, "son of the great Wapashaw," before proceeding north on his first expedition. On September 23, 1805, he held a council with seven Mdewakanton "chiefs" to negotiate the purchase of 100,000 acres of land so that the United States could build a fort at the mouth of the Minnesota River. The Treaty of St. Peters, also known as Pike's Purchase, was signed by only two of the seven Mdewakanton leaders present, including Chief Little Crow I and Penichon.

In April 1806, after spending the winter with the Ojibwe and with fur traders in the north, Pike returned to the mouth of the Minnesota River (to what is now known as Pike Island) and held another council with the Dakota. This time, more than forty chiefs from the Sisseton, Wahpeton and Mdewakanton Dakota bands attended, together with 500 tribesmen. The Ojibwe had refused to attend the proposed peace council organized by Pike, and had sent him away with pipes, which the Dakota chiefs accepted and smoked. However, a few Dakota objected to reconciliation with the Ojibwe, and Pike was unable to convince any Dakota leaders to accompany him to St. Louis for further talks as he had hoped.