Prosecutors had recommended a sentence of 46 to 57 months for Mr. Jackson, who pleaded guilty in February to one count of felony fraud, while his lawyers had requested 18 months. Mr. Jackson was also sentenced to three years of supervised release, and he is not eligible for parole. But his sentence could be reduced by several months for good behavior or if he receives treatment for his bipolar disorder. He also must pay back the campaign money to the government.

A lawyer for Mr. Jackson, Reid Weingarten, described him as a “good man” whose illness sometimes clouded his judgment. But Judge Jackson said that “manic episodes” could not explain the more than 3,000 times that the Jacksons used campaign money to make personal purchases, including $15,000 in kitchen appliances and a $43,000 Rolex.

“There may be gray areas in campaign finance,” she said. “This case did not come near to those areas.”

Prosecutors had sought 18 months in prison for Ms. Jackson, a former Chicago alderman. Ms. Jackson, who pleaded guilty to one felony count of filing false tax returns, must also pay $22,000 in restitution and is subject to one year of supervised release.

A lawyer for Ms. Jackson, Dan Webb, sought to portray his client as a doting mother whose absence would cause deep psychological damage in the children. He had requested a sentence of probation with community service.

In rejecting that request, Judge Jackson said to Ms. Jackson: “The court did not put your children in this position. The government did not put your children in this position.”

The sentencing marked a precipitous downfall for Mr. Jackson.

With the help of his father, the Rev. Jesse Jackson, Mr. Jackson was elected to Congress in 1995 from a district that includes part of the South Side of Chicago. He became one of the most prominent young black politicians in the country, working on issues related to health care and education for the poor.