President Joe Biden formally signed the biggest climate package in U.S. history Tuesday night, cementing the $430 billion Inflation Reduction Act into law. The legislation, hailed by former President Barack Obama on Tuesday evening, is aimed at cutting domestic greenhouse gases and fighting climate change, as well as improving health care and reducing the price of prescription drugs. Just after Biden signed the legislation at the White House event, he handed the pen to Sen. Joe Manchin (D-WV), who was crucial to passing the final version of the bill. “Joe, I never had a doubt,” Biden said. After the event Manchin described the gift of the pen as “a nice gesture. A very nice gesture.” When asked about his feelings about Biden’s pointed remark to him, Manchin described the president as “optimistic.”