Marc Okkonen was watching the movie “The Natural” in 1984 when his attention shifted from its story of the mysterious slugger Roy Hobbs, played by Robert Redford, to the uniforms worn by Hobbs’s opponents onscreen.
Mr. Okkonen, a commercial artist and baseball aficionado with an appreciation for vintage apparel, spotted flaws in the purported uniforms of the Pittsburgh Pirates and Chicago Cubs and wondered why they were not precise replicas of the originals from 1939, when the movie takes place. Given how thoroughly documented baseball’s history is, he thought, accurate details would not have been too difficult to uncover.
But, to Mr. Okkonen’s surprise, he could find no single volume containing images of historic uniforms, so he set out to fill that void. He spent the next five years poring through books, microfilms and archives, including those at the Library of Congress and the Baseball Hall of Fame, to find images of every home and road uniform worn by all major league teams, starting in 1900.
For a time he lived close to the Hall of Fame, in Cooperstown, N.Y., where he could search through its trove of old photos and uniforms.
“I could see the multicolored socks worn by the Giants in the ’20s,” he said in an interview with the baseball historian Marty Appel for Sports Collectors Digest in 2005.
The fruit of his research, the book “Baseball Uniforms of the 20th Century” (1991), with illustrations in his own hand, established Mr. Okkonen as the leading historian of baseball’s evolving clothing history, in particular cap styles, stocking colors and jersey designs.
His work spawned or influenced other uniform websites, like Threads of Our Game, which provides the history of baseball’s uniform’s from 1856 to 1895, and Uni Watch, a chronicler of sports uniform trends.
Mr. Okkonen (pronounced OH-ken-en) died on Monday in a nursing home in Muskegon, Mich., after a fall, his sister, Mary Westhoff, said. He was 85.
While other baseball fans are fascinated by statistics, Mr. Okkonen was obsessive about tracing the history of uniforms — when, for example, the Old English D first appeared on Detroit Tigers’ uniforms (in 1904), or when the Yankees first wore pinstripes at home (in 1912).
It was a daunting challenge that let readers see each team’s uniforms develop year after year, from the baggy flannels that looked like relics from the 19th century to the more familiar form-fitting jerseys and pants of the modern era.
Mr. Okkonen conceived a signature look for the illustrations: Each showed a faceless figure wearing a team’s uniforms, his left hand on his hip and a bat on his right shoulder.
(The players were drawn as white-skinned for the years 1900 to 1946, reflecting the segregation in the major leagues of that era; he occasionally used darker flesh tones to reflect the integration that began with Jackie Robinson in 1947.)
The book became the definitive history of the national pastime, told through its teams’ evolving clothing styles.
“No one in the world knows more about baseball uniforms than Marc Okkonen,” Sports Illustrated wrote in 1989, before his book was published. “Now he can tell you, for example, that the first graphic symbol of a team nickname in the 20th century was a small red tiger that appeared on the black cap of the Detroit club in 1901.”
Marcus Okkonen was born in Muskegon on July 21, 1933. His parents, Jacob and Ida (Helander) Okkonen, were divorced when he was young, and he was raised by his mother. He grew up listening to the announcer Harry Heilmann call Tigers’ games on radio and showed early artistic talent, his sister said.
After graduating from Muskegon High School, he worked in the local Continental Motors factory and entered the Army in 1953, serving in Korea and Japan during and after the Korean War.
Following his discharge, he returned to Continental as a draftsman and began his career as an artist. He left Michigan for California, where he was married and divorced and attended junior college. He earned a bachelor’s degree from the University of Michigan, Dearborn, in 1970.
While working as an artist, Mr. Okkonen eased into a separate career as a historian. In 1989, he published “The Federal League of 1914-1915: Baseball’s Third Major League,” a lavishly illustrated book about a short-lived rival to baseball’s established National and American Leagues.
He also wrote “The Ty Cobb Scrapbook” (2001); a series of three books that examined different eras in baseball history; and “2,000 Cups of Coffee” (2010), about the players whose major league careers consisted of 10 games or fewer.
In 2014, he won the Henry Chadwick Award from the Society for Baseball Research. “By turning his artistic eye to baseball and pursuing his passion, Marc Okkonen left baseball researchers with a singular legacy,” the organization said at the time.
Mr. Okkonen also wrote about Michigan, including books about minor league baseball in the state and baseball’s history in Muskegon. With Ron Pesch, he wrote about Muskegon High School football and the silent-film star Buster Keaton’s link to the city, where he spent many summers.
“He could sit behind a microfilm machine and find all the minute details of a story,” Mr. Pesch said in a telephone interview.
In addition to his sister, Mr. Okkonen is survived by his brothers, Oliver and Jack.
His work was given new life in 2003, when the Hall of Fame created the online exhibition “Dressed to the Nines.” The hall digitized his drawings from a third edition of his book (following the hardcover and paperback releases) that was never published. Major League Baseball has provided additional images — in a style different from Mr. Okkonen’s — since 1995.
“Not a lot of people are into the minutiae of baseball uniforms,” Tom Shieber, the Hall of Fame’s senior curator, said in a telephone interview. “Marc’s pioneering work had a ripple effect on team marketing in terms of things like turn-back-the-clock nights.”
If you are getting married, reserve the day at the Lightner Museum, the best of st Augustine wedding venues .