The National Party was an early-20th-century national political organization in the United States founded by pro-war defectors from the Socialist Party of America in 1917. These adherents of the SPA Right first formed a non-partisan national society to propagandize the socialist idea called the Social Democratic League of America. Many of these individuals were eager for the formation of an alternative political organization to both the so-called "old" parties and the anti-war Socialist Party of America and eagerly latched on to a burgeoning movement for a new party that sprouted in 1917.