John Adam Pœrtner, Poertner or Portner (January 3, 1817 – July 7, 1910) was an American mason, miller and politician from Milwaukee, Wisconsin.
Pœrtner was born in 1817 in the Grand Duchy of Hesse, and emigrated to the United States, arriving in New York City on May 26, 1839.
[2] As of the 1850 Federal census, he was working as a mason, and married to Caroline Portner [spellings were not consistent], who was a 28 year old native of France, and they had four children.
By 1856, he was among the freeholders of the Sixth Ward to petition the Milwaukee Common Council for street improvements.
He died July 7, 1910, of "senile debility and exhaustion" and was buried at Union Cemetery in Milwaukee.