It is unknown when Hobbits first appeared in Arda. They are only known to have originated somewhere in the Valley of the Anduin River. By the time they were discovered by the other peoples of Middle-earth, they had already been around for many generations. The earliest known group of hobbits lived in the Valley of Anduin, in the region of Wilderland between Mirkwood and the Misty Mountains. According to The Lord of the Rings, they forgot any genealogical ties to the "Big People" (Men). At this time, there were three breeds, or tribes, of Hobbits, with different physical characteristics and temperaments: Harfoots, Stoors and Fallohides. While situated in the valley of the Anduin River, the Hobbits lived close by the Éothéod, the ancestors of the Rohirrim, and this led to some contact between the two. As a result, many old words and names in "Hobbitish" are derivatives of words in Rohirric.
About the year TA 1050, they undertook the arduous task of crossing the Misty Mountains. Reasons for this trek are unknown, but it possibly had to do with Sauron's growing power in nearby Greenwood, which was later named Mirkwood because of the shadow that fell on it, as Sauron was searching the area for the One Ring. The Hobbits took different routes in their journey westward, but as they began to settle together in Bree-land, Dunland, and the Angle formed by the rivers Hoarwell and Loudwater; the divisions between the Hobbit-kinds began to blur.
