Nygaard was born on a farm near Sharon, Steele County, North Dakota.

He was one of eight children born to Carl Nygaard and Anna Karene Grimson who had relocated from Decorah, Iowa.

He attended the public schools of Sharon, Mayville State Teachers College and the University of North Dakota.

Nygaard taught in the rural schools of Emmons and Steele counties from 1932 to 1935 and was engaged in the grocery and hardware businesses from 1936 to 1960.

On July 18, 1963, Nygaard entered the United States Capitol office of Dr. George W. Calver, physician to Congress, complaining of chest pains.