Policy-making was much more Congress-centered in the 19th century. The clearest examples of this are probably from the 1850s, when presidents Zachary Taylor and Franklin Pierce left the difficult task of dealing with the growing crisis of slavery to Congress. (Illinois Senator Stephen Douglas urged Pierce to support the Kansas-Nebraska Act of 1854, which he eventually did – rather than the other way around.) After the Civil War, presidents grew less passive, but members of Congress still asserted their own agendas on issues like tariffs and currency — the big economic questions of the time. Presidents were more likely to be led by their parties than to lead them.

So far, Trump has mostly followed the 19th-century model, even if that wasn’t exactly his intention. Despite his clashes with Senate Majority Leader Mitch McConnell over health care, Trump has not shown an interest in the details of policy. He hasn’t fully staffed the executive branch and hasn’t appointed staff or Cabinet officials with a lot of relevant policy experience. This reflects older patterns in which the national government was smaller and did much less, and presidents didn’t have the extensive professional staff they have now.