Heidelbach was born on 20 June 1814 in the village of Pfarrweisach in Bavaria,[1][2] where he was learning the butcher trade.[3] In 1837, he immigrated to the United States first settling briefly in New York City[4][5] where he invested all his money in $8 of merchandise which he converted into $150 after three months.[6] In the same year, he moved to Cincinnati where he continued to peddle, increasing his capital to $2,000 after a year.[6] In the early 1840s, he went into business with another Jewish peddler, Jacob Seasongood, founding dry good store Heidelbach, Seasongood & Co.[4][5] By 1860, they had a large clothing factory[3] which prospered making clothing and blankets for the Union Army with $1.2 million in sales by 1864[7] becoming the largest clothing manufacturer in the Mississippi Valley.[2] In 1861, he co-founded the bank Espy, Heidelbach & Co with a gentile partner.[4][3] In 1865, he moved to New York City and set up his own private bank.[4][3] In 1876, his firm was renamed Heidelbach, Ickelheimer & Co. after his son-in-law, Isaac Ickelheimer (married to Jennie Heidelbach Ickelheimer), became a partner.
Heidelbach was one of the first trustees of the Cincinnati Southern Railroad.[5] He served as president of the School Board of B'nai Israel and was active in the Hebrew Benevolent Society.[5] He was married to Hannah Heidelbach née Leeser.[8] The couple had six children together.[1]