The practice by a winning party of awarding government jobs to its members

In politics and government, a spoils system (also known as a patronage system) is a practice in which a political party, after winning an election, gives government civil service jobs to its supporters, friends and relatives as a reward for working toward victory, and as an incentive to keep working for the party—as opposed to a merit system, where offices are awarded on the basis of some measure of merit, independent of political activity. The term was used particularly in politics of the United States, where the federal government operated on a spoils system until the Pendleton Act was passed in 1883 due to a civil service reform movement.

Articles

Bureaucracy and the Civil Service in the United States, by Murray Rothbard, The Journal of Libertarian Studies, 1995
Historical account of the evolution of the United States Civil Service and attempts to reform it, from its beginnings through the early 20th century
"The 'spoils system,' a derogatory term for rotation in administrative office, was brought to the United States by President Andrew Jackson. ... he removed 252 out of 610 presidential class employees ... Whigs ... abandoned their principles ... Harrison and Tyler Administrations ousting fully fifty percent of the presidential class officials."
The Challenge to the U.S. Postal Monopoly, 1839-1851 [PDF], by Kelly B. Olds, Cato Journal, 1995
Analysis of the operation of the U.S. Post Office in the 1840s, including estimates of subsidies to various groups, and discussion of the private competitors and the effects they had on the postal service
"In the 1840s, over 80 percent of the nonmilitaty personnel working for the federal government were postmasters or postal clerks. The fact that each new administration caused heavy turnover in employees strongly suggests that service with the Post Office offered more than market wages. ... Under this schedule, payments to postmasters across the board dropped about 30 percent from the pre-1845 level. The Post Office had no problem finding men who would work for those rates. Postmasterships continued to be counted valuable spoils. Lincoln was accused of being more concerned with filling poetmasterships than with prosecuting the Civil War."

The introductory paragraph uses material from the Wikipedia article "Spoils system" as of 16 Oct 2018, which is released under the Creative Commons Attribution-Share-Alike License 3.0.