LOS ANGELES, CA.- A remarkable letter by Albert Einstein privately warned his eldest son that German industrial giant Siemens was anti-Semitic, years before the company would employ tens of thousands of Jewish forced laborers at Nazi concentration camps — is now up for auction at Nate D. Sanders Auctions, with bidding open through March 26. Opening at $32,000, the letter represents an extraordinary convergence of personal history, Jewish history, and the origins of the nuclear age.

A Father's Warning — Five Years before Hitler

Dated January 21, 1928, and written in German to his son Albert (known as "Hans Albert"), the two-page letter offers a remarkable window into Einstein's private concerns about antisemitism in German corporate life. Advising his son on job prospects in Germany's electrical industry, Einstein wrote: "Siemens has written you off. What else is there to consider? Siemens is — as far as I know — anti-Semitic. Doesn't AEG need such static saints as yourself? I have better connections there."

Einstein's warning was well-founded — and prophetic. By 1933, Siemens rapidly complied with Nazi demands to dismiss Jewish employees across its operations. By the early 1940s, the company was operating forced labor factories at Auschwitz, Ravensbrück, Buchenwald, and at least five other concentration camps, with Jewish prisoners performing 12-hour shifts manufacturing weapons components for the Reich. Siemens' own corporate records acknowledge that at least 80,000 forced laborers worked for the company between 1940 and 1945, of whom at least 5,000 were concentration camp prisoners. In 1998, the company established a compensation fund for survivors, and has since contributed more than €150 million in reparations.

Letters from Einstein to his eldest son Hans Albert are themselves exceptionally rare. Einstein notes this himself in the opening line: "I haven't written to you in a long time. But private letters are quite unusual for me." Hans Albert Einstein (1904–1973), a distinguished hydraulic engineer, went on to become a professor at UC Berkeley. The father-son relationship was warm but physically distant — Einstein's demanding scientific career and the dissolution of his first marriage left him geographically separated from both his sons for much of their lives.

Buried near the letter's close is a line of extraordinary historical consequence: "Technically, I am working more and more with Szilard."

The Szilard referenced is Leo Szilard (1898–1964), a Budapest-born Jewish physicist who had fled Hungary's anti-Semitic Horthy regime and landed in Berlin, where he became one of Einstein's closest scientific collaborators. Their partnership at the time Einstein wrote this letter centered on inventing a safer household refrigerator — one with no moving parts, eliminating the risk of toxic gas leaks that had killed an entire Berlin family. Together, Einstein and Szilard would file more than 45 patents across six countries, ultimately selling one design to Electrolux and negotiating with AEG — the same company Einstein recommended to his son — to develop their electromagnetic pump.

Their collaboration would eventually pivot to something far more consequential. On August 2, 1939, Einstein and Szilard co-signed a letter to President Franklin D. Roosevelt warning that uranium chain reactions could be used to build weapons of unprecedented destructive power. That letter — now known as the Einstein-Szilard Letter — is widely credited as the catalyst for the Manhattan Project. Szilard also contributed to the design of the first nuclear reactor and, later in life, worked tirelessly for arms control, founding the Council for a Livable World in 1962.