When did Lou Gehrig attend high school?
Lou Gehrig attended Commerce High School in 1917 and graduated in 1921.
Because Lou Gehrig died before middle school was invented, Lou Gehrig didn't attend middle school. According to Wikipedia, Lou Gehrig attended two schools in Manhattan: PS 132 and Commerce High School. For the grades that are now called Middle School (the term only dates back to the 1950s; Lou Gehrig died in 1941), he would have attended PS 132 for 5th through 8th grades and Commerce High for 9th grade.