My understanding is, it's referring to a claim to so much acreage for farming if you would build a "permanent" type dwelling on it and actually live there and farm it for some period of time--maybe five years, I don't know. Homesteading, in other words.
My step-father told me he had homesteaded in I think South Dakota in his youth, and he swore that every word of "The Lane County Bachelor" was true, in his experience. This would have been in the late 1800s, or MAYBE the first ten years of the century.
Dave Oesterreich