Typewriters vastly lower the cost of producing readable text. Before the typewriter people would have to either write carefully (slowly) or hire a calligrapher.
Mill patented the first typewriter in 1714. Nothing more is known about him; he has disappeared into history.
Christopher Sholes invented the QWERTY keyboard and typewriter ー the first commercially successful machine ー in 1873. He worked with printer Samuel Soule, with whom he’d invented and patented the page-numbering machine. Carlos Glidden, a lawyer and amateur innovator, also joined as a third partner, agreeing to fund the project.
James Densmore acquired one-fourth of the patent during development, buying it without seeing the typewriter by reimbursing the expenditures Sholes and his team accrued while creating prototype typewriters. Densmore worked on quality control, declaring the initial design that was essentially worthless except for the patent. In frustration, Soule and Glidden quit and assigned their patent interest to Sholes, leaving him owning 3/4ths of the patent and Densmore owning 1/4th.
Sholes and Densmore realized stenographers would be the key users so sent prototypes to them. James Clephane was one; he destroyed many typewriters. Densmore eventually came up with the idea of the QWERTY keyboard layout, which put commonly used keys on both sides of the keyboard, to coordinate key strikes and avoid jamming.
The company manufactured 50 typewriters, selling them for $250 each before approaching E. Remington and Sons (makers of firearms, sewing machines, and farm equipment) for manufacturing help. Instead, Remington wanted to buy the company.
Sholes sold Remington his 3/4th interest in the typewriter patent, in 1873, for $12,000. Densmore refused to sell and licensed his 1/4th of the patent for royalties, subsequently netting him $1.5 million.