Samuelson's work in macroeconomics was significantly influenced by John Maynard Keynes' "General Theory of Employment, Interest and Money." Published in 1936, Keynes' work revolutionized the field of economics by providing a framework for understanding aggregate economic phenomena. Samuelson, in his 1947 article "Foundations of Analytical Economics," and later in his textbook "Economics: An Introductory Analysis" (1948, with William Nordhaus), helped to popularize Keynesian economics, making it accessible to a broader audience, including students and policymakers.