Marc Lowell Andreessen is born in Cedar Falls, Iowa. He grows up 10 miles outside New Lisbon, Wisconsin, a village of 1,500, on Castle Rock Lake. His mother, Pat, works in customer service at Lands’ End. His father, Lowell, is a sales manager for Pioneer Hi-Bred International Inc. On his father’s job:
It was an Amway kind of thing–farmers slowly going out of business on their family farms sell seed corn to other farmers slowly going out of business.
He has one brother, Jeff, a history major at the University of Wisconsin. Andreessen discovers programming at age 12. While recuperating from an operation he persuades his parents to buy him a Radio Shack computer.