The paper discusses how Milton Friedman and Anna J. Schwartz's book "Monetary History" was influenced by various economists, with Wesley Clair Mitchell's work being the most significant. Mitchell's focus on long-term data analysis and the impact of money on the economy shaped Friedman and Schwartz's conclusions about the importance of money in influencing the business cycle. They disagreed with Mitchell's view on how money affects the economy but agreed that money plays a crucial role in shaping economic trends.