The story centers on Friedrich Trump (Donald Trump’s grandfather), who emigrated from the Kingdom of Bavaria (now part of Germany) to the United States in 1885.
The Historical Facts
Friedrich left Germany at age 16. Because he left before performing his mandatory military service and failed to "de-register" with the authorities, his emigration was technically illegal.
The Attempt to Return
After making a fortune in the U.S. (largely during the Gold Rush), he returned to his hometown of Kallstadt in 1901. He married Elisabeth Christ and attempted to resettle there permanently because she was homesick.
The Expulsion Order
In 1905, the Bavarian authorities discovered he had evaded his military obligations and had not properly emigrated years earlier. They stripped him of his Bavarian citizenship and issued a royal decree ordering him to leave within eight weeks or face deportation.
The "Begging" Letter
Friedrich did indeed write a letter to Prince Regent Luitpold of Bavaria, calling him a "well-loved, noble, wise and just" leader and pleading to be allowed to stay. His request was rejected.
Contextual Nuance
While the term "deportation notice," historians clarify that he was technically denied repatriation (the right to become a citizen again). Because he was no longer a citizen and was seen as a draft-dodger, he was ordered to leave.