On May 7, 1915, the day the _Lusitania_ sank, William P. Dempsey, the secretary-treasurer of the Atlantic Coast International Longshoremen's Union, met Dennis Driscoll, a Boston labor leader and former city office-holder, at the old Quincy House in Hanover Street. Driscoll said that Matthew Cummings, a wealthy Boston grocer, had outlined to him the plan for the strike, and said he was acting for parties who were willing to pay a million dollars. Dempsey maintained his poise when the startling information was recited, but he was frightened, and at the conclusion of the interview he telegraphed at once to T. V. O'Connor, the president of the union, requesting an interview. The two union men met in Albany and discussed the affair pro and con, arriving at the conclusion that they had best reveal the plot to the Government. O'Connor accordingly told of the negotiations to Secretary Wilson of the Department of Labor, and then in connivance with the Secret Service, went on dealing with the grocer, constantly pressing him for the identity of the principals who, he said, were prepared to supply all the necessary money. He implicated George Sylvestor Viereck, the editor of a subsidized German propaganda-weekly called _The Fatherland_, and said that he had been introduced to him by Edmund von Mach. Neither of those men figured except as intermediaries, and Cummings suggested that Dr. Bernhard Dernburg, a loyal propagandist then in the United States, was the director of the enterprises. Owing to the high pitch of public feeling over the _Lusitania_, Cummings could not receive permission from his superiors to go ahead with O'Connor, but he did his best to keep O'Connor interested. The latter, fearing that German agents were at work on the Pacific coast, took a trip to the far West, and during his absence Cummings telegraphed him twice. There the affair ended, for O'Connor ignored the message, and on July 14 returned to New York to find that a German attempt to force a walkout on the New York waterfront had failed, and that Cummings had stopped playing with fire and had gone back to his grocery in Boston.
When the Government turned the story over to a newspaper to publish on September 13, the time was not ripe to fix the responsibility for the attempt. Dr. Dernburg was a popular scapegoat at the time, and the implication of his authority in the attempt was allowed to stand. Rintelen was in Donington Hall, a prison camp in England, and it was months thereafter before the United States and British Secret Services had fully compared notes on him. By that time there were other charges lying against him which promised better cases than an abortive attempt to promote a strike 'longshore.