A former aide, Aaron Del Valley, 36, was convicted of one count of perjury for lying to a federal grand jury investigating Sanchez.
"We had a job to do and we did it, and now I'm sitting up here convicted of crime and I don't know what the crime is," Sanchez told reporters afterward.
U.S. Attorney Patrick J. Fitzgerald brushed aside claims that City Hall higher-ups, not Sanchez, were responsible for patronage hiring in his department.
"When you are commissioner of streets and sanitation you can't duck responsibility for what happens on your watch," Fitzgerald said. "If jobs are going to be awarded to people with clout, if people are rigging the system, that is a crime, that is a felony."
Fitzgerald also scoffed at the suggestion by defense attorney Tom Breen that jurors might have been biased against Sanchez because of heightened concern about political corruption in the wake of former Gov. Rod Blagojevich's impeachment.
"He's not the victim of a horrible political climate, he's the perpetrator of a crime," Fitzgerald told reporters.
It was the latest chapter in Chicago's long-running controversy over patronage -- the practice of reserving jobs on the city payroll for those who get out the vote.
Sanchez was a leader of the Hispanic Democratic Organization, a group of hundreds of campaign workers that support Mayor Richard M. Daley and other candidates who are supported by the mayor. Many members of the organization ended up with jobs in the 4,000-employee department of streets and sanitation.
The department is the largest in the city government, and is responsible for street sweeping, garbage collection, snow plowing and rodent control.
Breen portrayed Sanchez during the two-week trial as a poor boy who made good after growing up in "Slag Valley" in the shadow of the steel mills, fighting in Vietnam and overcoming bias against minorities to emerge as a major city department head.
Sanchez maintained on the witness stand and in talking to reporters after the verdict that he had suggested both Latinos and African-Americans for city jobs. But he said he merely made recommendations and had no power to hire anyone.
"But I guess that's a federal crime," he said.
Breen said Sanchez had inherited a system that had gone on for decades.
"This was done every day in every department and he has to wear the jacket for it," Breen said. Patronage has died hard in this city where vestiges of the once mighty machine still linger. Hiring based on politics for most city jobs is banned by a 1983 decree in a case brought by attorney Michael Shakman. He says he lost a seat at the 1970 Constitutional Convention because patronage workers campaigned for his opponent.
But the Shakman Decree has been largely ignored for decades.
The No. 2 man in the mayor's Office of Intergovernmental Affairs, Robert Sorich -- who was known universally around City Hall as the mayor's "patronage chief" -- is currently serving a 46-month sentence in federal prison for hiring fraud. Three other former officials were convicted along with him.
City hiring practices are currently taking place under the watchful gaze of a court-appointed monitor.