Why did Mark Twain begin giving public lectures in 1866?

Mark Twain (born Samuel Clemens) began his first lecture tour in 1866 as part of his commitment to establishing a professional career beyond journalism. Having already recognized that his "strongest suit" was humor, he sought to expand his reputation and audience. His initial tour, which focused primarily on his travels to the Sandwich Islands (Hawaii), proved to be a success.

Throughout his life, Twain viewed the lecture platform as a reliable way to generate income when needed, even though he personally found the process of touring to be grueling.1