Einstein-Levy-Schwarzschild household in the 1940 United States census

Two passenger manifests document the continuous 1939 route, and two federal censuses independently repeat the same San Francisco sibling household and address a decade apart.

Ludwig's naturalization file and draft card establish the same Stuttgart-born man, with the exact birth date 26 July 1880, at 3897 Clay Street. The 1940 and 1950 censuses directly call him Melita Levy's brother, and the 1950 census also calls Josephine Stone their sister. C-019 independently bridges Melita to Auguste, while C-009 establishes Auguste and Josephine as daughters of Emil Einstein and Karoline/Caroline Schweizer. The California death index matches Ludwig's exact birth date and reports his mother's maiden name as Schweitzer and father's surname as Einstein. Ludwig's 1939 manifests also name cousins in the Laupheim Einstein network and at 3800 Washington Street in San Francisco. Josephine independently named the same San Francisco cousin, Corinne Koshland; Corinne's signed passport uses the maiden name Schweitzer, and the likely Laupheim cousin Benno Nördlinger was a son of Pauline Einstein. This convergence makes the parentage and sibling relationship highly likely.