Mr. Fritz, 65, a writer and adventurer, began his political life as a liberal in the 1960s but shifted to libertarianism in the 1970s and clung to it to the very end.
His belief in individual liberty prompted him to run unsuccessfully for Congress on the Libertarian Party ticket in 1982.
"He was larger than life. He was an ardent seeker of truth and goodness. If he saw the truth, he'd change his life and conform to it," said Alan Schaeffer, president of the Alliance for the Separation of School and State, which Mr. Fritz founded. "He had a passion for religion, cultures and geography."
Mr. Fritz developed a political quiz in the 1980s called the "World's Smallest Political Quiz." The 10-question quiz helps someone find out where they belong on the political spectrum and has been widely circulated, particularly in Libertarian circles.
Born in Inglewood, Mr. Fritz began his career as an IBM salesman but then turned to the nonprofit world.
He established Advocates for Self-Government in 1984, now based in Georgia, to promote Libertarian ideals. He also established the now-defunct Pioneer Christian Academy, a kindergarten-to-12thgrade school that challenged the existing educational system. The school had no formal curriculum, no tests, no homework and no separation based on age or grade. Students for the most part taught each other.
In 1994, he founded the Alliance for the Separation of School and State, a group that encouraged parents to pull their children out of public schools and educate them at home or in private schools. At his death, he was board chairman.
His friends described him as a devout Catholic, an intellectual and a world traveler who loved to eat.
"As he traveled all these different places, he was delighted to try the local food," said longtime friend Virgil Swearingen of Fresno.
"He loved to eat everything," Swearingen said.
Fritz was active in the Christian Businessmen's Committee, Serra Club, Toastmasters, a nonprofit that hones communication and leadership skills, and Overeaters Anonymous, a group that focused on eating habits. Fritz volunteered at a homeless shelter and coached youth soccer.
He was the publisher of two newspapers, The Educational Liberator and The School Liberator.
One of the biggest issues he opposed was allowing government to run public schools.
"He was for freedom from government tyranny, and he started three organizations in Fresno that were devoted to freedom from government tyranny," Swearingen said.
"Among freedom-oriented people he was probably as well known as anyone in the freedom movement. It seems they all knew and respected him," he said.
Fritz is survived by his wife of 44 years, Joan Fritz; his son, Eugene Fritz of Calwa; his three daughters and their husbands, Susan and Christopher Bethea of Clovis, Lucie and Tony Ruiz of Fresno and Ann and Kyle McKenna of Pittsburgh; 12 grandchildren; and his brother, Russell Fritz of Baja California, Mexico.
A Catholic Mass will be celebrated at Our Lady of Perpetual Help parish, 929 Harvard Ave., Clovis, at 5:15 p.m. today. A graveside service will follow at noon Saturday at the Holy Sepulcher Cemetery in Orange.
In lieu of flowers, remembrances may be made to the Marshall Fritz Lectureship Fund at 1071 N. Fulton St., Fresno 93728.