In the middle of the night, Friedrich Trump left his house in Kallstadt, a small town spotted with vineyards and a Lutheran church, for a northern port city that served as Germany’s gateway to America.

A few days later, on Oct. 7, 1885, Friedrich, then 16 years old, bought a steerage-class ticket on the S.S. Eider, the start of an adventurous life as a barber, restaurateur, saloonkeeper, hotelier, entrepreneur, gold rush prospector, shipwreck survivor and New York real estate investor.

It was an immigrant tale that would make any family proud. But for decades, the Trumps almost never talked about it.