This article presents and analyzes the most comprehensive database to date of significant acts of Congress—from 1789 to 2010—to test whether divided party control of government affects the number of important acts Congress passes. We find that unified control corresponds with one additional significant act passed per Congress in the nineteenth century and four additional such acts in the twentieth century. However, party control of government cannot explain the broad historical trends in the rate at which Congress passes significant legislation. Nixon in 1969 was far more successful with a Democratic Congress than was McKinley in 1897 with a Republican one.
Ansolabehere, Stephen, Maxwell Palmer, and Benjamin Schneer. "Divided Government and Significant Legislation: A History of Congress from 1789–2010." Social Science History 42.1 (Spring 2018): 81-108.