Before he secured the first of his 61 patents — inventing everything from refrigerated trucks to movie-ticket dispensers — Frederick McKinley Jones was down on his luck.

It was 1913. Jones was 20. He'd just been fired from his job as a mechanic in Cincinnati — for racing cars on company time. With work hard to find for a biracial son of an Irish father and African-American mother, Jones moved north and landed work as a Minneapolis hotel janitor.

One of the guests, Oscar Younggren, watched Jones fix a boiler and offered the young janitor a job. The job, servicing steam tractors on a 50,000-acre farm, took him nearly 400 miles away, outside the northwestern Minnesota hamlet of Hallock (population nearly 1,000 in 1920).

Jones stayed in the tiny town near the Canadian border for nearly 20 years, sandwiched around his stint as a master repairman for the U.S. military during World War I. He would later tell the Saturday Evening Post that Hallock was the kind of place "where a man … [was] judged more on his character and ability than on the color of his skin."

That open-mindedness contrasted with a rough childhood. Jones was born across the Ohio River from Cincinnati in Covington, Ky. His father was a railroad worker and his mother left the family when Jones was an infant.

Struggling as a single father, the elder Jones turned to neighboring orphanages. But they wouldn't take a boy of color. So Jones' father left him, at age 7, with Father Ryan at a local Catholic church. The priest encouraged the kid's habit of tinkering as the young Jones cleaned the rectory. Two years into his church stay, Father Ryan told Jones that his father had died.

Coming of age just as cars did, Jones took an early interest in auto mechanics — often tuning up parishioners' cars during services. He quit school at 11 and bolted from the church, which he considered too rigid and dull. He ran away to Cincinnati and quickly found work sweeping up a car-repair garage.

By 15, he was the garage's foreman and an avid car racer. His boss thought he was too young to race and fired Jones for pursuing his passion during work hours.

He drifted around fixing steamships, furnaces, tractors and cars, eventually landing in Minnesota in time for the fateful meeting with the Hallock farm manager. Jones left the farm around 1915 but remained in Hallock, working on cars until the U.S. entered World War I in 1917.

Jones was placed with an all-black unit in France until military honchos realized his innate mechanical ability. He was soon in high demand, promoted to sergeant and asked to work as an electrician — wiring telephones and telegraphs, fixing X-ray machines, repairing vehicles, you name it. He even taught classes to fellow soldiers on electrical circuitry.

Returning to Hallock after the war, Jones added movie theater projectionist to his repertoire — developing machinery to sync soundtracks with no-longer-silent films. He also built an early radio transmitter for Hallock and helped area doctors make house calls in unique fashion during snowy northern Minnesota winters.

Jones' "snow machine" featured skis on an airplane fuselage with a propeller zipping doctors around Kittson County. He responded to doctor complaints about long distances between patients by developing a portable X-ray machine.

A Minneapolis movie theater entrepreneur named Joe Numero hired Jones as an electrical engineer in 1927 to improve film sound quality at his Cinema Supplies company. By the late 1930s, Jones landed his first patent for a movie theater ticket machine — an idea he later sold to RCA.

Around that time, in 1938, Numero was golfing with an associate in the freight business, who had just lost a shipment of chickens. The birds overheated and died in transit when the trip took longer than expected.

Numero mentioned the problem to his mechanical guru and, within weeks, Jones had come up with the prototype of the refrigerated semitrailer truck.

Together, Numero and Jones left the movie theater business to form Thermo King, which mushroomed into a large commercial refrigeration enterprise. More than 40 of Jones' 61 patents would come from the refrigeration business.

By 1943, Jones' Model C refrigerator truck became so popular, military officials used it to keep blood chilled during World War II. He went on to fine-tune his air-conditioning machines for military field hospitals, which needed to store blood serum for transfusions.

Jones remained in Minneapolis, serving as Thermo King's chief engineer, until he died in 1961 from lung cancer at 67 — leaving his widow, Lucille. After his death, he became the first black inventor to receive the National Medal of Technology, in 1991. He was also the first African-American granted membership in the American Society of Refrigeration Engineers in 1944. He was inducted into the Minnesota Inventors Hall of Fame in 1977.

In a profile in the Saturday Evening Post, Jones' climb from orphaned school dropout to prolific inventor was summed up like this: "Most engineers start at the bottom of a project and work up, but Fred takes a flying leap to the top of the mountain and then backs down, cutting steps for himself and the rest of us as he goes."

Staff researcher John Wareham contributed to this report.

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com .