Macross Island was a small island in the South Pacific where a massive alien spaceship crash landed in July of 1999. A large portion of the island's land mass was blown away by the force of the impact, but remarkably, much of the spacecraft remained virtually intact. Upon examination by a top-secret task force of scientists, the spaceship was determined to be of military origin. Fearing that more hostile alien forces would follow, an alliance of Earth governments took control of Macross Island and began reconstructing the vessel. Over the next ten years, the new international community of Macross City swelled as a massive portion of the world economy was tapped to rebuild the vessel, which was christened the Super Dimension Fortress-1.
Another section of the island was destroyed in 2009 when a boobytrap mechanism aboard the SDF-1 was activated and fired the ship's Main Reflex Cannon at an incoming Zentraedi scout ship, sparking the opening battle of the First Robotech War.
All of Macross Island's remaining land mass, including Macross City, were accidentally transported to Pluto orbit when the SDF-1's spacefold system malfunctioned. The United Earth Government subsequently declared the entire population dead and blamed the destruction of the island on the then-defunct Anti-Unification League in a massive coverup effort to keep the existence of the Zentraedi a closely guarded secret.