The SDF-1 was originally the Flagship of the mysteroius Robotech Masters which controlled most of the Galaxy through there knowledge of Robotechnology.  Zor one of their brilliant, and foremost expert on Protoculture, which was cultavted from the Invid Flower of Life.  Zor stole the ship in attempt to reseed the Invid flower of life on planets. During a reseeding operation on a unknown planet the Robotech masters attacked it, in attempt to keep it from falling into the hands of the Robotech Masters, Zor programmed the ship to a series of Jump points eventually ending at earth. When all of this was happening Earth was in a middle of WW3,  In the Year 1999 somewhere over the south pacific, the SDF-1 which was dubbed "The Vistor"  at the time  folded in earthspace, and eventually crashed landed on a remote south pacific Island Macross.  Days after the landing a ceasefire agreement came into affect, and a small team of researchers led by Dr. Emil Lang, made a discoveries One that earth was not alone , and that someone will be coming to look for this.  Of course this prompted the immediate ending of WW3, and the formation of the United Earth Government (UEG) , and later the Robotech Defense Force (RDF) was also formed. Within ten years of the crash landing   great technological advancements including project valkrie, which the battliod Configuration of the Veritech Fighters where Top secret to the Public due to the fact the aliens where 50 feet tall, and Project Tomahawk , which was the Destroid program being overseen by Colonel Anatol Leonard . 

Ten Years Later, the Zentradi which was led by Breetai finally caught up to the SDF-1 and folded into earthspace, and eventually the began the First Robotech War. After a year in space, and it's final battle defeating Dolza, the SDF-1 was destroyed above New Macross City, which resulted in it being buried into three mounds.