His Remarkable Circle

Ingersoll revered Lincoln deeply, though they never met in person. After the war, Ingersoll delivered some of his most moving orations praising Lincoln's emancipation of the enslaved and his skeptical, self-made mind. In his famous lecture 'A Vision of War,' Ingersoll invoked Lincoln as the embodiment of American reason over superstition. Ingersoll believed Lincoln shared his own quiet skepticism about orthodox religion.

Twain and Ingersoll were great mutual admirers and personal friends. Both shared a sardonic wit, a deep skepticism of religious orthodoxy, and a passionate belief in human dignity. Twain called Ingersoll 'the most brilliant speaker I ever heard,' and Ingersoll admired Twain's ability to use humor as a surgical instrument against hypocrisy. They appeared together at events and corresponded warmly throughout their lives.

Walt Whitman held Ingersoll in the highest esteem, calling him one of the greatest Americans of the age. Ingersoll defended Whitman's 'Leaves of Grass' at a time when it was widely condemned as obscene, praising Whitman's celebration of the human body and the natural world. Ingersoll delivered a celebrated funeral oration at Whitman's graveside in 1892, a moving tribute to a kindred spirit.

Ingersoll and Douglass shared a profound commitment to human liberty, equality, and the abolition of slavery. They appeared together on the lecture circuit and were mutual admirers. Ingersoll, a fierce supporter of Reconstruction and the civil rights of formerly enslaved people, saw their causes as one: the liberation of all human beings from arbitrary authority — whether of state, church, or master.

Ingersoll was an early and outspoken champion of women's suffrage and women's rights. He argued passionately that women deserved full equality before the law and in public life. Susan B. Anthony respected Ingersoll's advocacy and they were allies in the struggle for human rights, though Anthony's Quaker faith and Ingersoll's agnosticism meant they approached the question from different directions.

Ingersoll and Elizabeth Cady Stanton were close allies. Stanton shared Ingersoll's deep skepticism of orthodox religion, which she believed was a primary tool of women's oppression. Her later work 'The Woman's Bible' reflected ideas that Ingersoll championed throughout his career. They corresponded, appeared together, and found common cause in both freethought and the liberation of women.

Ingersoll and President Grant were close personal friends. Ingersoll was a loyal Republican and a staunch defender of Grant's character when political enemies attacked him. When Grant lay dying of throat cancer in 1885, Ingersoll visited him and later delivered one of his most celebrated orations at a memorial meeting — a passionate tribute to Grant's perseverance and humanity.

Thomas Edison deeply admired Ingersoll, calling him the greatest orator he had ever heard and one of the most intellectually honest men of the age. Both men shared a belief in human reason, science, and progress over superstition. Edison's own religious views — skeptical, naturalistic — mirrored many of Ingersoll's positions. Edison preserved Ingersoll's voice on one of the earliest phonograph recordings.

The steel magnate Andrew Carnegie was an admirer and friend of Ingersoll. Both were self-made men who believed in reason over religion and the power of education. Carnegie's philosophy of giving back — building libraries across America — resonated with Ingersoll's belief that knowledge freely disseminated was the great liberator of mankind. They moved in the same New York social circles in Ingersoll's later years.

Though Ingersoll never met Darwin personally, he was one of the most passionate American advocates for Darwin's theory of evolution. Ingersoll saw natural selection as the scientific key that unlocked humanity from creation myths. He defended Darwinian evolution from pulpit attacks, argued it was entirely consistent with a moral life, and credited Darwin with being one of the great liberators of the human mind.

Thomas Paine was Ingersoll's greatest intellectual hero and inspiration. Ingersoll delivered his famous oration 'Thomas Paine' in 1870, rescuing Paine's reputation from decades of slander by religious critics who sought to erase his deist and freethought legacy from American history. Ingersoll saw Paine as the truest of the Founding Fathers — the one who dared say aloud what others only thought in private.

Eva Parker Ingersoll was the center of Robert's world. In an era when women were legally subservient to their husbands, Ingersoll treated Eva as his full equal and partner. He refused to include the word 'obey' in their wedding ceremony. She was his confidante, his intellectual companion, and his greatest supporter. He called her 'the finest person I have ever known.' She survived him and remained a keeper of his flame.

Voltaire was one of the great intellectual ancestors Ingersoll claimed. Ingersoll saw himself as carrying forward the Enlightenment tradition: attacking superstition with wit, reason, and courage. He frequently quoted Voltaire and held him up as an example of the freethinker who suffered for truth. In 'The Great Infidels,' Ingersoll praised Voltaire as one of humanity's greatest benefactors.