In the 19th century, the greatest questions concerning American citizenship were whether this new modern experiment in large-scale republican self-governance could work at all, and whether its initial reliance on slavery could be overcome. The answers proved to be that a large-scale republic centered on commercial, not martial aspirations could indeed endure, and that it could achieve the elimination of chattel slavery, though not without enormous costs. In the 20th century, the major issues became whether formally equal citizenship could be extended to all adults, regardless of race and gender. The answer proved to be that women and non-whites could gain genuine possession of the franchise and access to public office, even if only through great civic struggles, and even if those gains still left the nation far short of achieving practical equality in many spheres of public and private life. Though much remains to be explored in regard to those past developments, it is obviously timely now to ask, “What are the major issues facing American citizenship in the 21st century?” It is also tempting to speculate about how laws and public policies will deal with them, though that quest of course carries us out over even thinner ice.