On Friday, April 14, 1865, as the Civil War was drawing to a close, Joseph Henry left Washington with his daughter, Helen, and headed to New York City to inspect a fog signal under consideration by the United States Light-House Board. Leaving Helen in Princeton, New Jersey, where the Henry family had lived before Henry became Secretary of the Smithsonian in 1846, he continued to the city. After arriving at the Astor Hotel around 10 pm, Henry had a late supper, wrote a letter to his wife, and went downstairs to put his letter in the mailbox before going to bed.
While he was downstairs, he overheard a man who had just returned from the telegraph office with a report that President Lincoln had been shot. Although Henry later wrote that "the news was at first considered a hoax," [Marc Rothenberg et al., eds., The Papers of Joseph Henry (Science History Publications, 2004), v. 10, p. 498] he feared its "correctness, at least in part,"  and it was soon confirmed by others. Henry went to bed but was unable to sleep. Around 6 am the next morning, he asked someone passing by in the hall for the latest news from Washington and was told that the president was dying. Lincoln died at 7:22 that morning.
Before leaving the city later that day, Henry noticed that it "was in a state of intense excitement on account of the death of the President. Large bodies of men were seen gathering in squads at various points and fears were intertained that there would be outbreaks of popular feeling" [The Papers of Joseph Henry, v. 10, p. 499]. He completed his business and proceeded to Philadelphia where he attended church on Sunday and spent Monday conducting business involving Smithsonian publications. He found that city "much excited and popular feeling strongly against the south" [The Papers of Joseph Henry, v. 10, p. 499]. On Tuesday, April 18, he hurried back to Washington, arriving at his home in the Smithsonian Institution Building around 7 pm. There he found a letter from the Secretary of the Treasury asking whether Smithsonian officials would attend Lincoln's funeral. He replied immediately that they would [[The Papers of Joseph Henry, v. 10, p. 503].
The next day, Henry attended the funeral ceremony in the East Room of the White House with Assistant Secretary Spencer F. Baird and Smithsonian Treasurer William Winston Seaton. Although stands had been erected so that the six hundred attendees crowded into the room could see as well as hear, Henry thought the service should have been conducted in the rotunda of the Capitol to accommodate more people. Following the ceremony, Henry, Baird, and Seaton shared an open carriage in a massive funeral procession of some 40,000 people from the White House to the Capitol. Eight days later, Henry wrote to his friend and mentor, Alexander Dallas Bache:
On the day of the funeral more persons were assembled on the streets of Washington than was ever seen before in this city. All business was suspended and every countenance wore an expression of sadness. Mr. Lincoln had been constantly increasing in popularity, from the time of his reelection until the day of his death. His peculiar fitness for bringing the war to a successful termination was felt by all and the shock produced by his death cannot be described. [The Papers of Joseph Henry, v. 10, p. 509]
To his daughter Helen, Henry wrote:
As to his successor I can as yet say nothing, but I most sincerely pray that the mantle of Lincoln may fall upon him, that he may be imbued with the same honesty of purpose, the same kindness of heart, and the same moderation and prudence of action. [The Papers of Joseph Henry, v. 10, p. 504]
Although Henry had entertained doubts about Lincoln when he was first elected in 1860, he had gotten to know him well while serving as one of his science advisers during the war. By the time of Lincoln's assassination, Henry had come to admire and respect him and believed that only the president would be able to heal the divided nation. Henry mourned both his personal loss and that of the country.
- Joseph Henry: A Life in Science - Civil War, online exhibition, Smithsonian Institution Archives
- "Interruptions and Embarrassments": The Smithsonian during the Civil War, by Kathleen W. Dorman
- The Papers of Joseph Henry