Where were John and Mary born, and any censuses you have found them on?
Added:
That 1910 census gives Mary's parents both as German, and John's immigration year as 1880. Just showing as John Voight, not John L F Voight.
Also, Mary has been married 32 years.
Added:
In 1900 he appears as Frederick Voight, living with Paul and Mary, and his immigration year is 1850, so misread the year from 1910.
Fits with Mary A born in New Jersey in August 1858.