Eli Lilly announced plans for four new pharmaceutical manufacturing sites to produce domestic medicine production in the United States and make the nation the world's leader in pharmaceutical production.

Eli Lilly said Wednesday it will build three manufacturing plants in the United States to make the key raw ingredients in its medicines, a push to bring home a critical part of the pharmaceutical supply chain that largely comes from foreign sources.

Over the last few years, as Eli Lilly has revealed a series of manufacturing investments—each one seemingly more lavish than the last—the company’s spree has begged the question: What will they do | At a press conference in Washington,