Generation 1, as the fans call it, ran from the years 1984 to 1990 in the U.S. The line first introduced mechanical robots with the ability to "transform" into terrestrial vehicles, and objects. Later on throught the series they would eventually evolve into more complicated forms and advanced transformations.Over the following years fans would be introduced to the movie and post movie toys as well as the "Masters" lines. Up to the last year of g1 where the figures no longer transformed.
Year 1: First appearaces of the Autobots and Decepticons. First G1 autobot cars and Decepticon Jets, First Optimus Prime and Megatron.
Year 2: Introduction of more autobot cars and Jets, as well as giants such as Omega Supreme and the first combiner "Devastator".
Year 3: Post movie appearances of futuristic Autobots, as well as giant city-like transformers. More Combiners added to the line and also triple changers.
Year 4: First appearance of the "Masters" line with the Headmasters and Targetmasters.
Year 5: First apperance of the Powermasters, Micromasters and the Pretenders.
Year 6: More additions of the Micromasters and pretenders line.
Year 7: First apperance of the Actionmasters line as well as more additions to the Micromasters line. G1 american series ends.