But his arrival marked the beginning of the Trump family's life, adventure and misadventure in the United States. Years later, the teenager would begin amassing his fortune. He would marry Elizabeth Christ, a girl from his home town. Together they would have three children. Their second child, Fred Trump, would expand the family's real estate portfolio by building housing developments in the 1940s and 1950s. He would marry Mary Anne MacLeod, and together, they would have five children. Their fourth child, Donald Trump, would become the most famous in the family, the 45th president of the United States whose hard-line immigration policies would have prevented his family's patriarch from coming to the United States. US President Donald Trump's administration has been hard on unaccompanied minors. Historical records indicate Trump's grandfather arrived in the US on his own as a 16-year-old. Credit:Bloomberg Under today's policies, Friedrich Trump would have been considered an unaccompanied minor, or an "unaccompanied alien child," experts say, unless his older sister, who was his only relative in the United States when he arrived, had been appointed as his guardian. But generally, said Ohio immigration attorney David Leopold, many unaccompanied minors arrive with relatives already in the country. "Under President Obama, he would've been put into what people in the immigration world called the rocket docket. They would expedite his removal and prioritise it," said New York immigration lawyer Matthew Kolken. The same would have happened under his grandson's administration.

Trump was born on March 14, 1869, in Kallstadt, a village of less than 1000 people in the Pfalz region in south-west Germany. His family was not wealthy, not even middle class by modern standards. They owned and ran a small vineyard, but when Friedrich's father, Johannes Trump, died when he was eight, the family of six children was left deeply in debt. The siblings who were old enough to work helped in the vineyard, and Katherina Trump scraped more money by baking bread while caring for her children, according to Blair. But the family was still barely surviving. Loading Friedrich, the youngest of the sons, was too frail to work in the vineyard. So his mother sent him to a neighbouring town to learn to become a barber. He worked seven days a week, opening the barbershop every morning and sweeping the day's cuttings every evening, Blair said. Two-and-a-half years later, he went back home as a man with a trade and ready to work, only to realise that Kallstadt was too small to need another barber. He could (and should) serve in the military, a requirement by the German government, but he wanted something else. "The stifling lack of opportunity in the village seemed to close in on him. Without any apparent opportunity for a better life, he saw what lay ahead was dreary, difficult, and poor," Blair wrote. "He seemed to have no choice but to leave."

One night, he wrote a note to his mother explaining that he was going to the New World, according to Blair's account of family lore. When Katherina woke up the next morning, her son was gone. Friedrich travelled moire than 560 kilometres to Bremen, Germany, the port city where he paid the equivalent of $US20 ($15) for a steerage class ticket on the S.S. Eider. Steerage class ticket holders were offered barely one meal a day. There were no baths and hardly any drinking water. By the time S.S. Eider arrived at the Castle Garden immigration center in Manhattan 10 days later, the stench was so bad that a shipping and railroad tycoon who lived across the street complained about the smelly immigrants, Blair said. Nevertheless, Blair surmised that Trump must have felt very excited. "America was dazzling in the imagination. . . . This country had welcomed immigrants. It's the land of opportunity where people – where it's possible to make an immense fortune, which was somewhere around zero chance of doing that in Germany in this little wine-growing village," she said.

Trump came to the country during the big wave of German immigration to the United States. The 1880s to the early 1900s was a period of high immigration for young migrants under adult age, said Manuel Orozco, a migration expert at the Dialogue, a think tank on Latin American issues. Immigrants, particularly northern Europeans, were not only welcome; they were needed. Although immigration was relatively free and open during the 18th and early 19th centuries, the federal government began placing restrictions as the number of immigrants rose. The Chinese Exclusion Act of 1882, for example, was enacted both because of economic fears and racist attitudes against Chinese workers. Other laws were also enacted to keep certain labourers from coming to the country. Loading In 1897, President Grover Cleveland vetoed a legislation that would have restricted immigration by requiring a literacy test that would require immigrants to read five lines from the Constitution. In his veto message, he said: "Heretofore we have welcomed all who came to us from other lands except those whose moral or physical conditions or history threatened danger to our national welfare and safety . . . we have encouraged those coming from foreign countries to cast their lot with us and join in the development of our vast domains, securing in return a share in the blessings of American citizenship."

New York City was, in many respects, a German city. Trump lived with his older sister, who had moved to the United States the year before he did, in Manhattan's Lower East Side. His neighbours spoke his language, and the familiar smell of German bread, like the one his mother made back home, filled the air on Sundays, Blair wrote. He worked as a barber, but it was not enough for Trump. He moved to the Pacific Northwest years later to make a name and fortune for himself during the Gold Rush era. He opened businesses – hotels, taverns and restaurants, usually located in red-light districts – at frontier mining towns. "He was already shrewd enough and focused enough to realize that the money was mining the miners and not mining itself," said Blair, who was careful not to say that Trump ran brothels. "I think we don't quite know that." By the early 1900s, he was a wealthy and married man and an American citizen. But his wife, Elizabeth Christ Trump, was never able to call the United States her home. The family went back to Germany in 1904. The town welcomed them with open arms, but high-ranking government officials did not. They ordered Trump to be deported because he avoided serving in the military when he was a teenager. Trump brought his pregnant wife and young daughter back to New York, where they lived in an apartment in a German neighbourhood in the South Bronx. Months later, Elizabeth gave birth to Frederick Christ Trump, who would become the president's father.

Friedrich Trump died at age 49 in 1918. His famous grandson would be born nearly 30 years later. Washington Post