It’s hard to say because my mother’s side of the family is mestizo (Mexican); it is quite possible that some of her ancestors lived in what is now the Southwestern United States before the first Europeans arrived. My father’s father’s family apparently came here from Germany sometime in the late 19th century, and I only have vague information about my father’s mother’s ancestry.
I have American Indian ancestors on both my father’s and mother’s sides of the families, so I answered before 1492. After that, I have Dutch (one of who married an Indian woman) and then English ancestors (Thomas Pell among them) who settled in New Netherland (later New York) in the 1600s, and Germans who settled in Pennsylvania and Maryland in the 1700s. By the early 1800s, most of my ancestors were in Ohio (including some Christianized Indians). My ancestor who most recently immigrated was an Irishman in mid 1800s to Ohio. Most of my relations are still in Ohio.
I’ve married a Korean, so my descendants will have a more recent immigrant ancestor.
Wow, I thought I misread the poll choices at first - I figured they were all decades in the 1900s. I literally know almost nobody whose ancestry I know and whose earliest ancestor came to the US before 1900. My own wife is an exception though, at least on one side of her family, where they arrived in the 1880s.
Yet 1600-1700 is the most popular response so far? Wow.
But that’s what growing up in NYC earns me, I guess…
I have no clue. I know my last ancestor came here in the 1890s, but the others were either slaves or Spanish and were here before then. I wish I did know.
Mayflower - Another descendant of Wm. Brewster (hey cousins!)
I have traced my mother’s side to the 1700’s and Dad’s side to the 1800’s. ironically, my mothers was not American. She was Canadian but she has ancestors that fought in the American Revolution. On the good side.
I believe it was the very early 1900s.
My dad’s parents and my mom’s grandparents all arrived in this country before 1910. I don’t know the specific dates but I know when the American-born ones were born, so that helped narrow it down.
Before 1492, to account for a couple of Native American ancestors.
Otherwise, Jamestown, 1622. An ancestor arrived as an indentured servant that year. (But then he soon got married, and we don’t know his wife’s ancestry. She may have been there earlier.)
How far back can you track Cherokee? Whatever that date was.
My braggart of a rich uncle put together a self-published book on the history of the B’s. They came from England in the late 1600’s and settled in New England. His mother (my grandma) was French Canadian, no idea of her history (there are still relatives we know of living there). She was born in the early 1900’s, married a New Englander, and lived here in upper NYS… Now - on my mother’s side, her parents came from Russia (an area they used to call White Russia decades ago) in the early 1900’s and lived here in upper NYS. No idea of their background, if anyone is still living in The Old Country, how and why they got here (there was a whispered rumour my maternal grandfather (descended from a Cossack) was fleeing a murder rap!). All very sketchy. No one noteworthy in family history, just part of the milling mass of wretched immigrants!
Let’s see. I’m a quarter American Indian. The rest is mostly Mexicans and Spaniards who lived in Texas when it was annexed to the US in 1846. So in a sense we didn’t come to the US, it came to us.
My birth father’s parents came over in the early 1900’s, from Finland.
I am the first of my family to be born in the US. My parents got here around 1960, but they got to Canada (from Australia) in 1956.
On my father’s side, both of his parents arrived as children in the 1880s. His father’s siblings were mostly boys, and his mother’s siblings were mostly girls, so I have one set of double-cousins, where one of my grandfather’s brothers married one of my grandmother’s sisters. Apparently my great-grandfather, from Mecklenberg(sp?) had no intention of letting his sons serve in the Prussian army, so he uprooted the whole family and brought them here to the American midwest.
On my mother’s side I’m pretty sure I have an ancestor who was in the army during the Civil War, but I’m not sure how much farther back the family goes. I’d guess at least 1830 or so, since he seems to have been established here, not a recent immigrant.
I put between 1492 and 1600 but it turns out that the earliest I know of is Col. Thomas Pettus who arrived in Jamestown in 1637.
Whenever the Jacobites got exported to the US – on my mother’s side. Father’s side, about 1800’s when the Germans got kicked off the Russian Volga. Hmmm…seems a common thread here.
My father came here in the 1950s from Ireland. My mother came in 1959 by airplane, also from Ireland. (They met here in Chicago, as they came from near-opposite ends of the Republic.)
No Mayflowers in my family history, unless there was an airliner with that name. 
(I forget the name of the steamship my father crossed in, but I’m sure it wasn’t Mayflower.)
Jacob Slaughter born 1732 in the black forest area of Germany came to the U.S. on a ship called the Chesterfield.They landed in Philadelphia Not sure when.They migrated south to Granville county N.C.
I went for pre-1492, My grandmother was Native and that went as far back as anyone in the family had a knowledge of their ancestry, which was pretty far.
My three other grandparents were all immigrants, as it works out, during the 1930s. War refugees, in the main.