It's to be assumed that Spike and his father, Sparkplug, met the Autobots early on in their time on Earth. Spike had a younger brother named Buster, yet it was Spike who formed a close friendship with Bumblebee. The exact details of the Witwicky's early years as the Autobots' human associates are not known.
Somewhere in the time after 1984, Spike married Carly, who then gave birth to Spike's son, Daniel. After the explosion of the Ark II in 1999, which caused the death of Spike's father Sparkplug, Spike tried to leave his involvement with the Transformers behind and settled down with his wife and son in Cleveland, Ohio, trying to live a new life as a normal family. The newfound peace wouldn't last for long, though, as Spike was soon recruited by a shady military official named General Hallo seeking his help in reviving Optimus Prime, whose body his men had recently found in the Arctic. Spike, who had been entrusted by Prime with a fragment of the Matrix, used that fragment to bring Prime back to life.
Prime subsequently used the Matrix to revive and assemble a group of his Autobots, which he would then lead against Megatron's Decepticons. Meanwhile, Spike was imprisoned by General Hallo, who had double motives behind reviving the Autobots and even tried to kill them by bombing them. With the help of Larry, the World's Most Resourceful Janitor, Spike was able to escape his cell and uncover Hallo's sinister schemes, but not in time to stop him from launching a nuclear strike against the Autobots which was ultimately averted when Superion sacrificed his life in order to make it detonate before it could reach its target.
Following these events, Spike once again returned to his family and tried to leave his past with the Transformers behind. A few months later, though, his old friend Bumblebee, who had just decided to quit the Autobot army following a fierce battle against Sunstorm, showed up by his house. Spike, frustrated that the Autobots refused to leave him alone, hurled a few nasty insults against his old buddy before changing his mind and joining him on a men's night out in the city.