Sigmund Rosenberger was born in Bad Kissingen on September 12, 1883. His father was the cattle dealer Isaak Rosenberger from Schonungen who was married to Hanna Löwenthal who came from a long-established Jewish family of Bad Kissingen. Presumably, Isaak Rosenberger had moved to Bad Kissingen after the marriage and was awarded citizen’s rights by the Magistrate in 1873. Sigmund Rosenberger was the youngest of the five children of the couple and grew up in Pfarrgasse. From 1893 to 1898, he attended Kissingen Realschule, the predecessor of contemporary Jack-Steinberger-Gymnasium. Afterwards he apprenticed for becoming a baker.

In July 1905, he married Regina Lämle from Rülzheim/ Palatinate and moved into her home village after their wedding. There, in October 1905, the twins Cornelia and Rudolf were born. In 1913, their youngest son Hugo was born. For many years, Sigmund Rosenberger ran the matzo bakery in Rülzheim he had taken on from his father-in-law. It supplied the whole of Southern Germany with matzo. In May 1919, he was awarded citizens’ rights of Rülzheim by the parish councilors. In September 1918, the Rosenbergers sent their oldest son Rudolf to Kissingen Realschule which had also been attended by his father. By the way, both sons were talented football players. In 1921, Rudi played in the youth team of Rülzheim, whereas his younger brother Hugo as a goalkeeper even got as far as the youth selection of Southern Palatinate (See: Information obtained from Community Archive Rülzheim, mail by Carina Joseph from December 17, 2018). Rudolf Rosenberger emigrated to the United States already in 1926. His younger brother Hugo followed him there. Sigmund Rosenberger and his wife emigrated to the USA as well in April 1934 after the Nazi dictatorship had established itself in Germany. Their daughter Cornelia (called Nelly) had married the owner of a cigarette factory, Siegfried Schwarz from Landau in July 1929. They also managed to escape to the USA.

In 1940, Sigmund Rosenberger lived (according to US Census) with his daughter Nelly and her husband in a shared apartment in New York. His wife had already died in June 1938. Sigmund Rosenberger died in March 1958 in New York at the age of 64.