The Wisconsin State Patrol says the man's vehicle was spotted traveling westbound near Lake Delton on Sunday about 2 p.m. A trooper pulled him over and arrested him without incident.
Minnesota authorities say the 33-year-old man broke into a St. Louis Park house through the back door Sunday about 1 a.m. He allegedly assaulted the boy's mother and fled with the child, and authorities believed he was heading for New York or Florida.
He was arrested in Lake Delton, which is about 220 miles southeast of St. Louis Park.
The state patrol says the child was safe and napping in the back seat. Authorities made arrangements to reunite him with his mother.