Why do we have primaries?
It turns out that the direct primary system got its start in Pennsylvania. Crawford County, Pennsylvania created the direct primary system in 1842. The local Democratic Party there had a chaotic and ultimately failed county convention that year whereupon no slate of candidates was nominated. In the machinations that followed, they ultimately dealt with the situation by implementing a novel idea of allowing all Democrats to cast equal votes for who would represent the party in elections scheduled that fall. Seems like a normal enough idea now, but it was not how things were done back then. The idea was so well liked that it transformed from a provisional measure to the permanent method of selecting party nominees. While the idea spread throughout the state and nation, it was not an overnight change. It would not be until later in the late 19th/early 20th centuries that most states converted to direct primary elections. Pennsylvania would not have a comprehensive law requiring primaries until 1913.