When we think of American migration in the mid-1800s, the imagination often wanders to images of wagon trains and pioneer families trudging westward across the plains. "Westward, Ho!" was a reality, a great immigration spurred by the opening of new territories and the California Gold Rush. Our "one-way" vision of migration toward only the west has been perpetuated by Hollywood movies. The reality was not so tidy.
Our ancients actually the ability to travel in all directions! The first steamboat on the Mississippi, the major North-South waterway, was launched in 1811. The first transcontinental -railroad was completed in 1869 and connected the east to the west. From the 16th century onward ships crossed the Atlantic bringing new immigrants to the US and American visitors to the Old World. Sure people migrated to isolated homesteads on the Great Plains, however others flocked to the small towns that grow on rivers and rail lines. With various modes of transport in place, our ancestors were more mobile than their film stereotypes.
For nearly ten years I've been engaged in a surname research project (Tennessee Pryors). I continue to be amazed at how far people traveled and where they went causing them to disappear from the census and other public records for years at a time. When you can not find an ancestor in an expected location, then, try searching records in the unexpected places I've discovered.
Eastward, Ho! For some pioneers life in the frontier was just too unforgiving. When crops failed and homesickness set in, some of our ancestors went back to their eastern homes. Some cautious people when faced with the uncertainty of what was in store for them in the Wild West, never sold their eastern land. So, just because an ancestor was found in the west and then disappears from records, do not discount their possible return to their original community or nearby areas. Pay attention to birthplaces on the census: while investigating a family in Virginia I found one of their children was born in Missouri. That opened the door to finding them on Missouri census records.
Washington, DC. When you know a family was educated and held social prominence you may find them in Washington, DC or surrounding areas. Like today, successful families back to their community by running for political office. If in doubt, Wikipedia has numerous lists of political offices and who has held them.
France, Mexico, and Indian Territory. Before Louis and Clark, St. Louis was a pioneer town in the part of France (and for a time Spain) that would become the State of Missouri. More than 20 years before the Mexican War and the annexation of Texas, Stephen Austin took a group of American pioneers into an area of Mexico that would not become Texas until after the fall of the Alamo. Other pioneers headed into Indian Territory to establish homesteads or trading posts. Sites like the Missouri Secretary of State Digital Heritage have some territorial records. Often records are in the form of letters to territorial governors or land grants that have to be translated from Spanish or French, nor have they been transcribed into digital documents, so a meticulous search is needed to find reference to these pioneer families.
Travel Abroad. One family I research appeared to be deceased or forgotten in the census records. They were in the South up to the 1860 census and then they were gone. It was not until I playfully searched the UK Census that I found them. Business had caused the family to move abroad. The UK Census provided the clue and subsequent searches of ships' manifests and passenger lists cave the details of their return to the US-landing and setting in the North after the Civil War. The Canadian Border Crossing records on Ancestry are also helpful to the researcher.
Lost ancestors? All are not lost! With some diligent detective work in the unexpected places, you may find ancestors who you thought were missing.