I was doing some research on J.P. Morgan. (Ok, research backstory: In the summer 1919, he was summoned, er, subpoenaed by the Senate Foreign Relations Committee. They wanted to ask him why he had a copy of the draft peace treaty with Germany in 1919 before it had been released to the public. I found the testimony here via Google Books. Turns out, Thomas W. Lamont was both a partner at J.P. Morgan & Co. and attached to the US Delegation in Paris.)

There are a ton of Wall Street-DC connections, but while I was reading, I ran into this set of grim events from July 1915. At around 11:40pm, on July 2, 1915, a bomb exploded in the Senate Reception Room, adjacent to the Senate Chamber. A clear picture of the damage (via Library of Congress) is here:

The July 4 front page headline from the Washington Post connected the bomber, who received his PhD from Cornell University, with this explosion and the attempted murder of J.P. Morgan: