When you find your early ancestors listed in different censuses living in different counties, you may think they had the "pioneer itch" and were moving further west with each census. Back when I was researching my Stahl family line in early Pennsylvania, I initially concluded that they must have moved several times -- from Cumberland County to Bedford County to Somerset County and finally to Westmoreland County. But no, western Pennsylvania was just being settled in the late 1700s and early 1800s. County boundaries shifted as the population increased in the new area and local governments reorganized. While our ancestors may have lived on the same piece of real estate for decades, records of their births/marriages/deaths/property transfers could be recorded in several different locations. It's important to be aware of this possibility so you know where to conduct research. Generally, the record is maintained by the county with jurisdiction at the time the event occurred.

A week or so ago I mentioned my husband's Irish-born great-great-uncle, Michael Hickey, who in 1857 was granted pre-emption rights in Ramsey County, Minnesota Territory. I'd requested Michael's homestead file from the National Archives and Records Administration (NARA) but hadn't pored over every detail until recently. Here are a few facts that are obvious from the NARA documents (once I finally spent the time to decipher the poor copies and almost-illegible handwriting):

• Michael became a naturalized U.S. citizen in Oneida County, New York, on 5 December 1855, after residing in the United States for at least five years.
• The affidavit of Michael Carroll, a neighbor living about five miles from Michael Hickey's claim in Ramsey County, stated he'd known "Mr. Hickey" since 18 April 1856 and further, that Mr. Hickey had commenced living on his claim about 12 May 1856. Carroll's affidavit included many facts about the improvements made on the property and concluded with the statement, "Mr. Hickey is a single man about thirty five years of age."
• Michael Carroll's affidavit and Michael Hickey's pre-emption claim document were dated 25 February 1857.
• The property was described as the South Half of the Southeast Quarter of Sec. 20 and North Half of Northeast Quarter of Sec. 29, Township No. 33N of Range No. 24W.

The 1860 census would show Michael's brother, Bartholomew Hickey, living with his family on a farm in Anoka County. I'd always wondered why they'd settled so far away from Michael's property in Ramsey County. Maps can be a genealogist's best friend. But only if you look at the right map. When I pulled up plat maps online and found Range 24W and Township 33N, I found the described piece of real property just south of Lake George, in Oak Grove Township, Anoka County.

Wait a minute! In 1860, Bartholomew and family were living in Oak Grove Township, Anoka County. Ah-ha! Possibly on Michael's farm? When was Anoka County organized anyway? Did I repeat the bad reasoning about county boundaries that led to my incorrect assumptions about the Stahls in western Pennsylvania? From page 93 of Anoka County (Minnesota Historical Records Survey, 1942):

One of the early acts of the first territorial legislature which convened in 1849, was the organization of eight counties, viz: Ramsey, Benton, Washington, Itasca, Wabasha, Wahnata, Mahkahto, and Pembina. Rum river was the dividing line between Ramsey and Benton counties, and hence the territory now embraced in Anoka county was partly in each. In 1856 Sherburne county was detached from Benton, and that portion of territory lying east of Sherburne county and west of Rum river was also detached and became a part of Ramsey county. By an act of the Territorial Assembly passed May 23, 1857, so much of Ramsey county as is embraced within the following described limits, was organized into a separate county, to be called Anoka county... Anoka County was thereby established although subsequent legislation would further alter its boundaries. When Michael became owner of the pre-empted real estate in February 1857, it was part of Ramsey County. Three months later it became part of Anoka County. That's where I'd need to look for records of what happened to Michael's property.  And Anoka County - not Ramsey County - might be where Michael and Bartholomew's mother died in 1858 or 1859. There are many helpful on-line sources for contemplating county boundaries. Here are just a few:

1. Atlas of Historical County Boundaries, maintained by The Newberry Library:  http://publications.newberry.org/ahcbp/
2. Historical Atlases and Maps of U.S. and States:   http://www.mapofus.org
3. For Minnesota, the map collection at the Minnesota Historical Society: http://collections.mnhs.org/maps/