It was going to be a school that the Alhambra School District, the County of Los Angeles, and the cities of Alhambra, Monterey Park, and the "Wilmar" section of unincorporated Los Angeles County would be proud to call their own. Mark Keppel High School was going to bring much-needed relief to an Alhambra High School bursting at its seams from a population explosion. In 1921, AHS counted a student body of 900 students, but Midwesterners seeking a more temperate climate and refugees from hard-hit Depression and Dust Bowl states swelled the numbers until, by the mid-1930's, the school population had grown to 3,700. Keppel alumnus Steve Salazar recalls the over-crowded conditions at AHS that necessitated the building of Mark Keppel High School: "There were just too many students for those classrooms. During lunch period, there was nowhere you could go to get away from crowds. Every classroom was filled to capacity. And remember, there was no air conditioning at that time. The conditions made it very hard for students to concentrate on their work, and occasionally tempers flared."

Mark Keppel High School opened its doors to its 1,526 students on February 5, 1940. Royce "Doc" Foster remembers that first day of school at Keppel for he was the second student to cross its threshold: "I was familiar with Mark Keppel High even before school opened for Spring semester, since my friends and I had climbed all over the scaffolds on weekends when the workmen were not there. On that first day of school, I set out on my one and a half mile walk. As I got nearer to the building, I saw another boy walking toward the entrance. It was about 7:15 in the morning, and I think at that moment both of us realized that we were going to be the first two students to enter the school. I began to walk faster, then he began to pick up his pace. As we converged on the entrance he broke into a run, and so did I. But he was about 5-8 and I was just 5-2, so he got to the front door and went in maybe two or three strides ahead of me. I was satisfied to be the second student to enter Mark Keppel, and we laughed about our little contest that nobody else saw."

Once settled into their everyday rhythm, students discovered that Mark Keppel High School in the 1940's provided them with both a common and a unique high school experience. The population was, from its first day, a mix of whites and Mexican-Americans. Alumni recall that participation in campus activities was generally open to all students and uniquely integrated.

Dolly Acuña ('47) remembers the sense of racial harmony of the student body during her Keppel years: "People pretty much got along. There were cliques, and they were by race, but I think that was mainly because we got together with friends who lived in our own neighborhoods, and the neighborhoods were racially divided. But as far as getting along, I think Keppel was pretty good in having different races with very few conflicts. We all had Anglo friends and Mexican friends, especially those of us who played on sports teams. I'm proud to say that I was voted president of the Mark Keppel High School Girls' Athletic Association in my senior year. The G.A.A. was made up of whites and Mexicans."

Mark Keppel High was a typical San Gabriel Valley high school. Phyllis Greenameyer ('45) described what her teen years were like while attending Keppel: "I think teenagers back then had more time than they do today. The pace of life was slower, and we had fewer choices for entertainment than today. For us, fun meant going to the movies. The Monterey Theater on Garfield and Hellman and the Garfield Theater on Valley Boulevard were the two closest movie houses.

"Football games were held on campus, and school dances in the gymnasium were very popular; however during the war years I remember that we could not have night games because of the blackouts, and we had to black out the windows in the gymnasium for dances.

"My friends and I would often ride the Red Cars. There was a line that went east and west where the San Bernardino Freeway is today. We could take that line and transfer to another which ran parallel to Alameda all the way to Long Beach. At Long Beach, we liked to go to the Pike and Rainbow Pier. There were rides and other amusements. I remember that the Pike would be very crowded on Sundays, like Disneyland is today. We also took the Red Cars to the beach.

"Many of my friends and I took part in church activities. During the war our church sponsored many activities to help people, and we volunteered because we thought we should do something to help."
Mark Keppel High School students indeed did their part in the war effort. At the time a boy could enlist in the service at 16 with his parents' consent, and the male population of the school dropped dramatically as many boys enlisted. From time to time Keppelites in uniform returned after boot camp to visit teachers and friends. ASB Cabinet reminded students to conserve valuable resources. Students helped out at area USO's. Many Keppelites wrote to pen-pals stationed in Europe and the Pacific as class projects. Students' expensive silk stockings gave way to more economical nylon and "Bobbie sox", and leather-soled oxfords were replaced by rubber-soled saddle shoes. When school administrators discovered that the rubber heels left unsightly marks on the gymnasium's hardwood floor, students were required to remove their shoes at dances, and the "sock hop" came to Keppel.

Mark Keppel High School alumni served gallantly in World War II. Although some students left Keppel to enlist in the armed forces, the majority join up immediately after graduation. A Gold Star Program was initiated at the school to honor the memories of Mark Keppel students and alumni killed in action during the war. More than 15 young men from Keppel were honored with a Gold Star.

By the close of the decade, Mark Keppel High School boasted an enrollment that had grown by some 300 students. World War II was four years in the past, and the Korean War had not yet begun. The country and the state was beginning to experience a healthy postwar economy, and Mark Keppel High School was preparing itself for the next ten years.