Marc was born Markus to a Jewish family in
Prague,
Bohemia. He emigrated to the
United States in 1846 with his mother Judith Eidlitz after the death of his father Abraham. Having served a four-year apprenticeship, he set up in business for himself in 1852 - the year of his marriage - and founded the construction firm,
Marc Eidlitz & Son in New York City. The firm built the
St. Regis Hotel and many other projects. Through his influence, the Masons Builders' Association of New York played a major role in founding the
National Association of Builders. In New York, he was President of the Building Trades' Club and of the Germanic Savings Bank. Eidlitz made his home at 123
East 72nd Street, where he died. He had four sons and a daughter. His son Otto Eidlitz took over the business after he died. His brother
Leopold Eidlitz was a well-known architect, as was Leopold's son,
Cyrus L. W. Eidlitz. Marc converted to
Catholicism and kept close ties to the German immigrant community, becoming president of Germania Bank in 1888. ==Selected commercial commissions==