Robert A. Millikan vaulted from obscurity to international fame on the strength of his classic experiment designed to measure the charge on the electron. His "oil-drop" method for determining the electron charge earned him the 1923 Nobel Prize for physics. He solidified his role as a leader in American science by presiding over the rise of the California Institute of Technology into a world-famous center of scientific research.

Millikan was born March 22, 1868, the second of six children, to Silas Franklin Millikan and Mary Jane Andrews Millikan in Morrison, Illinois. His mother, a graduate of Oberlin College in Ohio, served as dean of women at Olivet College in Michigan before moving to Illinois, and his father later earned a degree at the Oberlin Theological Seminary and became a Congregational preacher. The family moved to Maquoketa, Iowa in 1875.

Millikan graduated with high marks from Maquoketa High School in 1886. Following in his...