“Curriculum differentiation is the crucial issue.” A savvy 21st century quote? Hardly! This is a World War I-era statement. Differentiation isn’t brand-new. It had its genesis in the 20th century’s earliest years, influenced by the individual differences and progressive education movements, and the emergence of junior high schools. This presentation explores these early iterations of curriculum differentiation, their application to gifted students, and the strong influence of the individual differences movement. The work of luminaries in both general and gifted education such as Bagley, Hollingworth, Pressey, and Witty challenge notions that today’s emphasis on differentiation is anything new.