While on vacation from performing in his hit Broadway show In the Heights, Lin-Manuel Miranda read a copy of Alexander Hamilton by Ron Chernow, a biography of Alexander Hamilton. After finishing the first few chapters, Miranda began to envision the life of Hamilton as a musical, and researched whether a stage musical of Hamilton's life had been created. All he found was that a play of Hamilton's story had been done on Broadway in 1917, starring George Arliss as Alexander Hamilton. (Arliss reprised the role in a 1931 feature film adaptation, Alexander Hamilton, but to date there is no record of Miranda having seen it.)
Miranda therefore began a project titled The Hamilton Mixtape. On May 12, 2009, Miranda was invited to perform music from In the Heights at the White House Evening of Poetry, Music and the Spoken Word. Instead, he performed the first song from The Hamilton Mixtape, an early version of what would later become "Alexander Hamilton", Hamilton's opening number. He spent a year after that working on "My Shot", another early number from the show.
Miranda performed in a workshop production of the show, then titled The Hamilton Mixtape, at the Vassar Reading Festival on July 27, 2013. The workshop production was directed by Thomas Kail and musically directed by Alex Lacamoire. The workshop consisted of the entirety of the first act of the show and three songs from the second act. The workshop was accompanied by Lacamoire on the piano.
Of the original workshop cast, only three principal cast members played in the Off-Broadway production: Miranda, Daveed Diggs, and Christopher Jackson. Most of the original Off-Broadway cast moved to Broadway, except Brian d'Arcy James, who was replaced by Jonathan Groff as King George III.