Complex sentence: In 1820 Congress limited federal administrators to four-year terms, which led to constant turnover; by the 1860s and the Civil War, patronage had led to widespread inefficiency and political corruption.
Split into simpler sentences: In 1820 Congress limited federal administrators to four-year terms, leading to constant turnover. And by the 1860s and the Civil War, patronage had led to widespread inefficiency and political corruption.