Recent improvements in the data infrastructure at US statistical agencies have dramatically enhanced the ability to measure and study job creation and job destruction. The longitudinal data now permit the tracking of all firms and establishments in the US private sector in a comprehensive and integrated manner. This allows researchers to distinguish between the contribution of new firms and that of new establishments. In addition, firm entry, growth, and survival dynamics can be tracked in terms of organic changes instead of changes associated with mergers and acquisitions or other forms of business ownership changes. These new developments have led to a burgeoning literature on US firm dynamics. The recent literature has especially focused on the role of young businesses for job and productivity growth. The findings from that literature are the focus of the current article. The recent developments are discussed in light of the large literature on firm dynamics (in terms of both theory and empirics) that has developed over the past few decades.