Digital information drives participation in politics, the economy, and society. Yet great disparities exist as to which communities have access to the internet. In 2017, only half of residents of formerly industrial Flint, Michigan, had broadband or satellite internet at home, while over 90 percent of those in thriving Sunnyvale, California, in Silicon Valley, were connected. More recently, Covid-19 laid bare these persistent digital divides in both urban and rural communities, illustrating that broadband use is a fundamental resource for the future of opportunity in communities. While previous studies have examined the impacts of broadband infrastructure, they have indicated little about the extent to which local populations can afford and use the technology. Moreover, there has been limited scientific evidence on how broadband adoption matters for collective benefits. Including new data on broadband subscriptions from 2000-2017, and comprehensive analysis for U.S. states, counties, metros, cities, and neighborhoods, argues that broadband use in the population is a form of digital human capital that benefits communities as well as individuals. Broadband has a causal impact across all types of communities—for economic prosperity, growth, income, employment, and policy innovation. Yet there are urban neighborhoods and rural counties where as little as one-quarter of the population has a broadband subscription, even when mobile is included. As we build "smart" cities and communities, as economies and jobs continue to experience rapid change, and as more information and services migrate online, it is communities with widespread broadband use that will be best positioned for inclusive innovation, with the digital human capital to thrive.