In 19875, SPI published "Blue and Gray", its first quadrigame — four different battles using the same set of rules, packaged into one box. The four battles were "Shiloh", "Antietam", "Chickamauga", and Cemetery Hill. These were designed by Redmond A. Simonsen, Edward Curran, and Irad B. Hardy. The concept of the quadrigame proved popular, and pre-orders alone made "Blue and Gray" SPI's second-best selling game the month before it was published. Once released, it was SPI's top-selling game in July and August 1975.