The current trend toward corporate focus reverses the diversification trend of the late 1960s and early 1970s. This article examines the value of diversification when many corporations started to diversify. I find no evidence that diversified companies were valued at a premium over single segment firms during the 1960s and 1970s. On the contrary, there was a large diversification discount during the 1960s, but this discount declined to zero during the 1970s. Insider ownership was negatively related to diversification during the 1960s, but when the diversification discount declined, firms with high insider ownership were the first to diversify.