This paper discusses the importance of effective training and workforce development programs as part of a broader strategy to increase the competitiveness of American workers. Although rapid technological change and increasing global competition have delivered great economic benefits to the U.S. economy overall, the development of new and more productive industries has caused some Americans to experience significant declines in their earnings and job prospects; the Great Recession exacerbated these longer-term trends. Workers with less education and those who have been displaced from long-tenured jobs face particular challenges, and effective job training programs are an important component of policies to help these workers. The Hamilton Project proposes two general principles that can guide policy-makers in improving training programs to aid American workers: 1) training funds should be directed to programs with a track record of success in improving earnings for the specific target population and to those workers who can benefit the most from those programs; and 2) training programs should directly engage employer and industry partners, or actively guide students to career-specific training. (Contains 6 figures.) [This paper was written with the assistance from Dmitri Koustas, Karen Li, Kristina Gerken and Kaitlyn Golden.]