To what extent was the progressive movement of 1900-1920 an extension of reformers ideas and programs of the late nineteenth century?

Many of the ideas of
the Progressive era that became laws in the early 1900s had their roots in the reformers' ideas
of the late 1800s. For example, the Populist Party arose from a loose network of Farmers'
Alliances that developed in the late 1800s. These alliances wanted to ameliorate the conditions
of farmers by such measures as controlling railroad rates.

Teddy Roosevelt's
Square Deal instituted several of the ideas that had been proposed by Populists and the Farmers'
Alliances, such as controlling the rates charged by railroads. Teddy Roosevelt accomplished this
through the Hepburn Railroad Act of 1906, which allowed the Interstate Commerce Commission to
regulate railroad rates. In addition, the Populists proposed the direct election of Senators
(who were then chosen by state legislatures) in an effort to make the federal government more
directly democratic. This idea became reality in 1913 with the 17th Amendment to the
Constitution.

Prohibition, disallowing the sale and transport...