Divergent fertility trends in the course of development are commonly ascribed to differences in state action—that is, to government policy, deliberate or inadvertent. However, fertility outcomes can also, often more persuasively, be traced to differences in cultural and institutional inheritance and in the supply and growth potential of human capital. These are materials that states and societies find themselves endowed with—in brief, their legacy. In reality, legacy and policy are interwoven: policy actions build on some legacy elements and attempt to combat others. And there is a third set of factors influencing fertility outcomes, covering distinctive features of the economic and geopolitical environment and essentially fortuitous events—together termed circumstance. Legacy and circumstance can shrink or shift the policy space, helping to explain past failures in policy achievement. These broad considerations are the basis for a sketch of East Asian/sub-Saharan African contrasts in fertility transition over the last 50 years. The sketch points to missing avenues of policy action in the African case in seeking to overcome legacy obstacles.