At Philadelphia he spoke in Independence Hall on Washington's Birthday, and raised a flag. "Our friends," he said of it, "had provided a magnificent flag of our country. They had arranged it so that I was given the honor of raising it to the head of its staff. And when it went up, I was pleased that it went to its place by the strength of my own feeble arm. When, according to the arrangement, the cord was pulled, and it flaunted gloriously to the wind without an accident, in the bright glowing sunshine of the morning, I could not help hoping that there was in the entire success of that beautiful ceremony at least something of an omen of what is to come." On this very day, President Buchanan, in Washington City, was apologizing for permitting the American flag to be carried at the head of a procession that was marching to celebrate the birthday of George Washington! It was at Philadelphia that matters became more exciting. At that place they were informed of a plot to assassinate the President as he passed through Baltimore. This information came to them from a variety of sources entirely independent, and the various stories so nearly agreed in substance that they could not be disregarded. Most important of these informants was Allan Pinkerton of Chicago, one of the most famous detectives in the world. He had been personally with his assistants in Baltimore and knew the details of the plot. But Lincoln was neither suspicious nor timid, and was therefore disinclined to pay heed to the warnings of Pinkerton. At about this time the son of William H. Seward met Lincoln with confidential communications from his father. This gave other evidences of this plot, gathered by some detectives from New York City. These two sets of detectives had worked on the case; each party entirely ignorant of the other. Both got specific evidence of the plot. It was remembered, too, that since leaving Springfield ten days before, they had had at least two escapes. The track had been tampered with in a manifest attempt to wreck the train. A hand grenade had been found in one of the cars. It is not likely that this deadly machine was taken on the train merely for fun. The members of the party were deeply concerned about the Baltimore revelations. But it was hard to get Lincoln to take them seriously. With difficulty was he persuaded to follow Pinkerton's plan and enter Washington secretly. He consented to do this really out of consideration for the judgment of others, not that he shared their apprehension. On one thing, however, Lincoln was firm. He had made certain appointments for speaking _en route_ which he would not abandon. His promise had been given and would be kept. One was the flag-raising at Philadelphia, narrated above, and the other was to address the legislature at Harrisburg. "Both these appointments," said he, "I will keep _if it costs me my life_." These words suggest that he may have realized more of the danger than he was willing to show.