If you shake the family tree of Alphonsa "Al" Cannon, significant pieces of Black history will start to fall out.

Cannon's great-uncle Jasper Nall started a school for emancipated slaves in Alabama in the late 1800s and later dictated his memories for a book titled "Freeborn Slave: Diary of a Black Man in the South." Al's uncle Charles Cannon was a pilot taught by Alfred Anderson, who became the pioneering leader of the Tuskegee Airmen Program training Black pilots for the military.

Al Cannon himself was ahead of the times in the 1950s when he was hired to teach science at Roosevelt High School in south Minneapolis, then a predominantly white school. In 2018 he was inducted into the school's Hall of Fame, which also includes Medaria Arradondo, Minneapolis' first Black police chief.

"He was certainly a pioneer teaching school in a mixed environment," said his son Christopher, of Los Angeles. "He was a believer in education. It was pretty cool."

Cannon, 91, of Eagan, died of a heart attack on Oct. 24 at United Hospital in St. Paul. A nurse at the hospital told his son that she had been in his class, and broke into tears.

When Cannon was introduced at the Roosevelt Hall of Fame ceremony, the crowd jumped to a standing ovation. Cannon was so overwhelmed that he couldn't speak and gave the microphone to his son Kevin, who had flown in from Tucson.

Cannon was born in Corona, Ala., the son of a coal miner and a teacher. His son Chris said that education runs through their family.

Cannon earned a bachelor of science degree from Alabama State University in Montgomery and a master's degree in science education from Colorado State University in Fort Collins. He met his future wife, Jacqueline, when both were stationed at a military hospital in Colorado during the Korean War.

"He really enjoyed the accumulation of knowledge," said Kevin Cannon. "He got that from his mom and his great teachers in college."

Cannon followed Jacqueline to Minneapolis, where she worked as an anesthesiologist, and he landed a job as a substitute teacher at Roosevelt. He was quickly hired full time. He also taught graduate botany classes at the University of Minnesota from 1967 to 1970 while taking graduate courses.

Cannon taught at Roosevelt for 30 years, chaired the school's science department several times and taught advanced science classes on his own time. He also was active in the Minneapolis Federation of Teachers union.

His Hall of Fame plaque recognizes him as an early minority teacher at Roosevelt who was seen by colleagues as a friend and teacher with a passion for his profession.

"He enjoyed the process of teaching and took pride in it," Chris Cannon said. "We would be walking down the street and former students would stop us on the street and ask if that was Mr. Cannon. You would hear stories all the time that my dad was hard on students, but that he was still a great teacher."

Cannon's Hall of Fame plaque says that many of his students became doctors, nurses and teachers. He was remembered by students for his knowledge, teaching methods and kindness and considered a role model, especially for students interested in science, technology, engineering and math.

Cannon, who retired in 1984, was a talented handyman and cook known for smoking a turkey every Thanksgiving. He is survived by his two sons. A memorial service will be held at a future date due to COVID-19.