[2] Rockne was born in Harmony, Minnesota, to Norwegian immigrant parents.

Rockne received a degree from the University of Minnesota Law School in 1894.

Anton J. Rockne was a director and charter member of the Norwegian fraternal organization, Vosselag, at its founding in 1909.

In 1909 he was selected to serve as Speaker of the Minnesota House of Representatives, a position he held for two years.

His 44 combined years of legislative service tie him with Carl M. Iverson for the greatest length of legislative service in state history until Lyndon Carlson passed it on January 3, 2017.