Now a US citizen, Frederick was able to vote in Washington's first presidential election in 1892, 125 years before his grandson would be named the 45th American president.

Just two years later, he was on the move again. The discovery of gold and silver deposits in Monte Cristo, Washington caused a flurry of interest in the small town, which was further heightened by rumours that John D. Rockefeller (pictured), then the richest man in the country, had apparently invested in mining in the area.

Frederick sold the Dairy Restaurant and moved to Monte Cristo – but it wasn't gold he was after. Instead, he bought a patch of land, filed a spurious gold placer claim that gave him the exclusive rights to it, and built a new hotel, restaurant, and brothel to cash in on the number of miners passing through the area.

Frederick Trump: the life and wealth of Donald Trump's German grandfather