Smedley Butler was there and this was the precursor to the attempted coup that the industrialist fascists wanted Butler to participate in.
During his Senate campaign, Butler spoke out forcefully about the veterans bonus. Veterans of World War I, many of whom had been out of work since the beginning of the Great Depression, sought immediate cash payment of Service Certificates granted to them eight years earlier via the World War Adjusted Compensation Act of 1924. Each Service Certificate, issued to a qualified veteran soldier, bore a face value equal to the soldier's promised payment, plus compound interest. The problem was that the certificates (like bonds), matured 20 years from the date of original issuance, thus, under extant law, the Service Certificates could not be redeemed until 1945. In June 1932, approximately 43,000 marchers—17,000 of whom were World War I veterans, their families, and affiliated groups—protested in Washington, D.C. The Bonus Expeditionary Force, also known as the "Bonus Army", marched on Washington to advocate the passage of the "soldier's bonus" for service during World War I. After Congress adjourned, bonus marchers remained in the city and became unruly. On July 28, 1932, two bonus marchers were shot by police, causing the entire mob to become hostile and riotous. The FBI, then known as the United States Bureau of Investigation, checked its fingerprint records to obtain the police records of individuals who had been arrested during the riots or who had participated in the bonus march.
The veterans made camp in the Anacostia flats while they awaited the congressional decision on whether or not to pay the bonus. The motion, known as the Patnum bill, was decisively defeated, but the veterans stayed in their camp. Butler arrived with his young son Thomas, in mid-July the day before the official eviction by the Hoover administration. He walked through the camp and spoke to the veterans; he told them that they were fine soldiers and they had a right to lobby Congress just as much as any corporation. He and his son spent the night and ate with the men, and in the morning Butler gave a speech to the camping veterans. He instructed them to keep their sense of humor and cautioned them not to do anything that would cost public sympathy. On July 28, army cavalry units led by General Douglas MacArthur dispersed the Bonus Army by riding through it and using gas. During the conflict several veterans were killed or injured and Butler declared himself a "Hoover-for-Ex-President-Republican".
In November 1934, Butler alleged the existence of a political conspiracy of Wall Street interests to overthrow President Roosevelt, a series of allegations that came to be known in the media as the Business Plot. A special committee of the House of Representatives headed by Representatives John W. McCormack of Massachusetts and Samuel Dickstein of New York, who was later alleged to have been a paid agent of the NKVD, heard his testimony in secret. The McCormack-Dickstein committee was a precursor to the House Committee on Un-American Activities.
In November 1934, Butler told the committee that one Gerald P. MacGuire told him that a group of businessmen, supposedly backed by a private army of 500,000 ex-soldiers and others, intended to establish a fascist dictatorship. Butler had been asked to lead it, he said, by MacGuire, who was a bond salesman with Grayson M–P Murphy & Co. The New York Times reported that Butler had told friends that General Hugh S. Johnson, a former official with the National Recovery Administration, was to be installed as dictator. Butler said MacGuire had told him the attempted coup was backed by three million dollars, and that the 500,000 men were probably to be assembled in Washington, D.C. the following year. All the parties alleged to be involved, including Johnson, publicly said there was no truth in the story, calling it a joke and a fantasy.