The Log Cabin Myth

Pioneers lived in log cabins... right? Well, it really depends on the period and the area in question. It also depends on your understanding of the definition of what constitutes a "log cabin". These excerpts from Hugh Morrison's Early American Architecture: From the First Colonial Settlements to the National Period help to explain:

Log House in Orillia Township, Ontario
1844 Picture by Titus Hibbert Ware

"By 'log cabin' we mean a dwelling built of round logs, laid horizontally on one another, with notched corners and protruding ends.... Spaces between logs, if any, are chinked with moss, clay, or oak chips.... the log cabin did not exist in any of the English colonies in the seventeenth century and was used very little throughout most of the eighteenth century. Neither did the Dutch use it in New Netherland, nor the French in Canada. It was a form of construction unknown in England, France, Holland, and southern Europe generally; it was likewise unknown to the American Indian.
...
It is tempting to believe that our early ancestors, gifted with ingenuity as well as courage, invented such an admirable solution to their urgent problem of quick and durable shelter. 
Apparently they did not. The English colonists did built blockhouses and prisons using logs hewn square and notched at the corners for either lapped or dovetail joints. This is indeed a superior type of construction, but it requires many tools and much skill and more time. The log cabin, if it had been known, would have supplanted the flimsy dugouts and cabins and wigwams the pioneer settlers actually built.
True log-cabin construction is thought to have been introduced into this country [the United States] by the Swedes when they settled Delaware in 1638.... In the eighteenth century, German settlers in Pennsylvania built large numbers of log houses, using both squared-log and round-log construction. Since most of the Germans entered the country by way of the Delaware valley, they must have acquired the technique from the Swedes...." (12-13)

Sources
Hugh Morrison's 1987, Early American Architecture
Harold Robert Shurtleff's 1939, The log cabin myth: a study of the early dwellings of the English colonists in North America

Further Reading
History News Network 2015, "Top 10 Myths About Thanksgiving"