I found additional information. On the 1880 Census Johnson Co,Spadra Twp,AR. He is listed as John Janson. Wife is listed as either Alice or Olive (index says Oliee)Janson. His occupation is shoemaker. Josie is listed as Josephine age 9, Charlie is age 5 and John M. age 1. All 3 kids born in AR. Also found him listed in 1870 Census- Pulaski Co,Little Rock,Ward 1,AR. He is listed alone apparently living with a Thrasher family. His occupation is shoemaker. Though it looks like it says born in Switzerland with Swedish language(which doesnt make sense). This census doesnt ask marraige status.
Also found elsewhere is a newspaper transcription that states John Janson married Olive T. Shipp in August 1867.