(covers information from several alternate timelines)
A cordial man, Patterson maintained a friendly relationship with Janeway, whom he referred to as "Katie" and described as "quick and smart," despite her insistence that she still experienced "nightmares" regarding his fractal calculus final exam. Upon boarding Voyager, Janeway was immediately quizzed by Patterson as to the threshold of the H2 molecule and the third-brightest star in Orion. After Janeway successfully answered these questions, Patterson gave Janeway a hug, and proceeded to conduct her on a tour of her new command and discuss her upcoming mission into the Badlands. When the pair entered the bridge, Admiral Patterson announced "captain on the bridge" at which everyone on the bridge sprung to attention. Patterson further agreed to look into Janeway's request to have Tom Paris assigned to the upcoming mission.
In an alternate timeline, both Patterson and Janeway encountered future Voyager crewmember Seven of Nine, who had been transported back in time from 2375 by 29th century Starfleet officers for the purpose of identifying a saboteur. Disguised as an ensign, Seven successfully interacted with Patterson and Janeway without contaminating the timeline. However, in another timeline created by a subsequent time travel event, Seven initiated a phaser fight with 29th century Starfleet Captain Braxton, in full view of both Patterson and Janeway. Both of these timelines were negated, however, when Janeway's counterpart from 2375 was able to prevent Braxton from initiating his plan to sabotage Voyager in the first place. (VOY: "Relativity")
The TNG short story, "Meet with Triumph and Disaster" in The Sky's the Limit, gives his first name as Theoderich and states he took over command of Utopia Planitia Fleet Yards in the 2360s, during construction of the USS Enterprise-D.