How did the existence of political machines necessitate the passage of civil service reform?

Political machines maintained by elite groups will try to get the vote on the election day by hook or crook to have political and administrative control of the region. The Pendleton civil service reform Act was pushed forward by vice president Chester Arthur after President James Garfield was assassinated by Charles Guiteau in 1881 who volunteered Garfield's election campaign and was disappointed when he did not get the post of an Ambassador.

Where’s the diagrams?

Iwould pick a true