The significance of the Pendleton Act in 1883 was that it marked a pivotal reform in the U.S. civil service system. The Act established that government jobs should be awarded based on merit rather than through political patronage, which had led to widespread corruption and inefficiency. It created the Civil Service Commission to oversee the examination and appointment of government officials. This reform aimed to professionalize the bureaucracy and curtail the influence of political machines. While it was a significant step towards a more meritocratic system, the implementation was gradual and faced opposition, but it laid the groundwork for modern civil service practices.