Final answer:
James A. Garfield was the president assassinated by Charles Guiteau, a disgruntled supporter who falsely believed he was owed a federal job. This event hastened civil service reform and the Pendleton Civil Service Act.
Step-by-step explanation:
The correct answer to the question is a) James A. Garfield. President James A. Garfield was assassinated by Charles Guiteau on July 2, 1881. Guiteau, a failed lawyer and a disgruntled former supporter believed he was owed a federal job and was entitled to an ambassadorship to France for his perceived role in Garfield's electoral victory. His extreme disappointment with being ignored for federal appointment led him to commit this tragic act against the President, which ultimately fueled the push for civil service reform and the eventual creation of the Pendleton Civil Service Act.
Guiteau spent significant time planning the assassination, considering various methods before settling on using a revolver as he wanted it done in an 'American manner.' His actions catalyzed change in how federal jobs were awarded, moving away from the patronage system that often rewarded political supporters without regard to their qualifications.