Your mission, should you decide to accept it (cue the Mission Impossible! music) is to:
Which family surname line (of identified ancestors) of yours stayed
the longest in one U.S. state or other country province/shire since,
say, 1600? For example, in the USA, my Seaver line was in Massachusetts
from 1634 to 1940. For England, my Vaux line was in Somerset from the
late 1500s to 1840. For Canada, my Kemp line was there from 1785 to
List the generations for one or two of your
long-staying-in-one-locality surname lines. (Yes, I know that some
countries used patronymics - follow the father's line back in time).
Well for the longest of any I have, from the Clan Forsyth group that they think my Forsyths moved to North Ireland from Scotland in the 1300 or 1400s and stayed there till my ancestors came to Pennsylvania in the mid 1750s, there William Forsyth built a house on the Monongahela River in 1775, and it was still owned by a Joseph Forsyth in 1985. I don't know if it is still in the Forsyth family. My part of that family moved into Kentucky and eventually Illinois in the 1800s.
For my Hansen family which because of Patronymics changed names each generation in Denmark, I found records back to the late 1600s and my grandfather left in 1887. My grandfathers dad died in 1892 but I know there are still some of the family in Humble Parish, Svendborg County, in Denmark.
When my grandfather married in Illinois his wife was from an old New England family the Dillinghams. Edward Dillingham b. 1595 in England and d. 1667 in Massachusetts came to Boston in 1632, settled in Lynn, Massachusetts. My branch of the family moved north into what is today Maine and stayed there till after the Civil War, but many of the Dillingham family are still in both Maine and Massachusetts today.
Edwards grandfather was born in Deane, Bedfordshire, England in 1548 and I found out they were there even earlier, but my family left in 1632 for Boston.