Delaware River, one of the principal water courses of northeastern Kansas, rises in Nemaha county, about 2 miles west of the city of Sabetha. At first its course is southeast through Nemaha, across the southwest corner of Brown and the northeast corner of Jackson county, until it enters Atchison county about 3 miles south of the northwest corner. From this point its course is more southerly through Atchison and Jefferson counties until it falls into the Kansas river nearly opposite the town of Lecompton. Its principal tributaries are Cedar, Plum, Gregg's, Walnut, Rock, White Horse, Big and Little Slough and Catamount creeks, and the Little Delaware river. Originally the stream was called Grasshopper river, but the visitation of grasshoppers in 1874 rendered the name unpopular and the legislature passed an act, which was approved by Gov. Osborn on Feb. 27, 1875, changing the name to Delaware river.