Since the late 1960s when the annual Summerfest music festival began, the event called for a headlining stage. The festival grounds are on patch of land that was formerly a nike missile site, just along the Milwaukee lakefront. Now called the Henry Maier Festival Park, the grounds have evolved into a well-maintained entertainment Valhalla. With the growing popularity of Summerfest from season to season, the ten-day run now draws over 800,000 people each year. 

The concept of building a venue such as the Marcus Amphitheater was preceded by valiant attempts to find a proper place on the grounds that could accommodate headline acts that draw 10,000-plus fans.  At first, a large stage was built on the north end of the festival grounds.  It had a bowed roof, and it was exposed to the elements.  The fans sat out in the hot sun on wooden bleachers.  That seemed to suffice in the early years.  The views of the stage, and amplification of the bands were not optimal, but Summerfest had a limited construction budget. They made do. Once Summerfest had amassed a sizeable amount of cash, they drew up plans for a venue that would be able to cater to 20,000 or more fans, and the amphitheater was the perfect fit.

Marcus Amphitheater is an outdoor amphitheater located on the south end of the Summerfest grounds. The building was completed in 1987. This seasonal venue plays host to musical performances and other events during the spring, summer, and fall. Though most shows are Summerfest related, other festivals such as the Vans Warped Tour and Lollapalooza have used the amphitheater as well.