Petersen was born in Glückstadt, Holstein-Glückstadt (now part of Germany but then ruled by the Kings of Denmark) on November 2, 1842.
Petersen came to Wisconsin in 1862, and settled in Appleton, where he was elected to various township offices .
Petersen was elected to the assembly for 1879 from Outagamie County's 1st Assembly district (The City of Appleton, and the Towns of Buchanan, Center, Freedom, Grand Chute and Kaukauna), receiving 1,096 votes against 1,000 for Republican B. T. Rogers (Rep.), and 423 for incumbent William Smith Warner (who had been elected as an "Independent Democrat" but was now the Democratic nominee).
[2] Petersen was not a candidate for re-election for 1881, and was succeeded by Democrat Henry Clay Sloan.
Petersen married Wilhelmina "Minnie" Freiberg,[3] born in Stettin, Pomerania in 1849; they were the parents of five children.