Over 120 years ago, the history of East High began. In 1874 a three story building was built on the present site. In 1876 a new East High School erected on the corner of Fifth and Mulberry. The present East High building opened in the fall of 1918. Since that time, East High has vastly grown in size. In 1939, the Music and Industrial Arts wing was added. The Fred J. Miller gymnasium was built in 1957, which started the idea of the "new wing". The cafeteria, boys' locker rooms, the new pool and twelve more classrooms were added in 1963.

Into the new millennium, East High started a multi-year renovation project.  A  new cafeteria was built on the site just south of the Fred Miller Gymnasium. The new area also houses a new practice gym, wrestling room. locker rooms and office complex. The 4th floor was also remodeled adding new classroom space.. The Elizabeth Green Auditorium underwent a 3.5 million dollar renovation in the summer of 2007.  And a new addition that will incorporate the Reggie Roby Fitness Center, coaches offices and locker rooms began in the fall of 2007.

Internally, there have been a number of changes in curriculum and in teaching-learning styles. In 1981, East High transformed from a three to four year high school. Currently the staff is working hard to improve student achievement by implementing Effective School Strategies, Freshman Houses,  Advisories and more rigorous and relevant lessons.  In 2005, East High was selected to participate in the Iowa High School Project and the Successful Practices Network.