Final answer:
President Chester A. Arthur was instrumental in moving Congress to support civil service reform by signing the Pendleton Civil Service Act of 1883, which created a merit-based system for government employment.
Step-by-step explanation:
The president who moved Congress to support civil service reform was Chester A. Arthur. After President James Garfield's assassination by a disgruntled office seeker, the need for reform became more pressing in the public eye.
President Arthur capitalized on this sentiment by passing the Pendleton Civil Service Act in 1883, which established the Civil Service Commission and significantly reduced the influence of patronage by requiring many government jobs to be filled according to merit, as determined by competitive examinations. The Pendleton Act set a precedent for a merit-based system and curbed patronage, marking the beginning of modern civil service in the United States.