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 it plans to build three new plants in the U.S. to make the key ingredients used in pharmaceuticals, part of a doubling of its investment in manufacturing.

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,