Evidently, in the first half of the 20th century, Franklin Park was the place to go air your grievances with whatever entity was keeping you down (i.e., The Man). It was to the point in the early 1950s that it was a nuisance to the neighboring businesses, hotels, and offices.
Source: Library of Congress
In April 1951, soap box orations were officially banned by the Interior Department. Below is an article, printed on April 10th, 1951 in the Washington Post.
Franklin Park, Sunday summer home of soap box speakers and their hecklers, no longer is open to public meetings.-ad 199-
Reason is that hotel men, rooming-house residents and business workers did some talking of their own to offifficials [sic] of the Interior Department’s National Capital Parks.
“If the orators had been content to speak in a normal tone and not use musical instruments to attract passersby their [sic] might not have been complaints,” said Edward J. Kelly, National Capital Parks superintendent.
The complaints, plus frequent fistfights, caused the decision to ban soap box orations at the park, between 13th and 14th sts. nw. Permits will be refused and park police told to break up any meetings.-ad 607-
However, Kelly made clear freedom of speech is not affected. The soap boxes, from which speeches on religion, world affairs, politics or any subject were delivered, may be moved to less troublesome areas, such as Judiciary Square or the Mall near Ninth st., provided permits are obtained.
At Judiciary Square court buildings should obstruct the noise, Kelly said. Since soap-box meetings usually are on Sunday, they wouldn’t interfere with court sessions he added.