The Orion Arm is a minor spiral arm of the Galaxy.
Human civilization first developed on the planet Earth in the Solar Starzone roughly four to six thousand years before the advent of the Common Era calendar. Humanity first became capable of space flight in the late 20th century CE, and began colonizing neighboring planets and satellites in the Solar Starzone by the middle of the 22nd century CE.
In 2391 CE, humankind discovered Warp technology, and by the early 25th century CE had begun the exploration and colonization of neighboring starzones in the Orion Arm of the galaxy. The first extra-solar colony to be settled was located in the Canopus Starzone. By 2620 CE humanity had settled dozens of worlds in a territory roughly 100 light-years in diameter. By 537 UC humans began to settle in the Sagittarius Arm of the Galaxy by way of the Iserlohn Corridor, and by 796 UC human colonized worlds in the Orion Arm filled up an area roughly 500 light-years in diameter.