What has a split Congress accomplished? A surprising amount.

The 117th Congress, which began with an unprecedented attack on the U.S. Capitol that personalized and deepened party divides, is preparing to head out of town having notched a surprising number of sweeping, often bipartisan, legislative accomplishments.

In the past six weeks alone, Republicans have joined Democrats in passing measures on gun safety, semiconductor manufacturing, helping veterans affected by burn pits, and approving Sweden’s and Finland’s accession to NATO. That’s in addition to last fall’s bipartisan infrastructure bill, which allocated $1.2 trillion to upgrading America’s roads, bridges, and other systems,...