Former Prince George’s county executive Jack B. Johnson pleaded for leniency Tuesday before a judge sentenced him to more than seven years in a federal prison for masterminding a corruption conspiracy that netted him as much as $1 million in bribes and implicated his wife and several developers, county officials and businessmen.

During a dramatic two-hour hearing at which Johnson (D) said his health is deteriorating, he apologized for the first time since his arrest.

“I’m sorry,” Johnson, 62, said. “I ask the people of Prince George’s County to forgive me.”

As a hushed standing-room-only crowd of mostly former county employees, preachers, and Johnson’s longtime friends and supporters looked on, U.S. District Judge Peter J. Messitte spared him the maximum 14 years in prison and imposed an 87-month sentence. Messitte also fined Johnson $100,000 and ordered him to undergo alcohol treatment and forfeit $78,000 and his antique Mercedes. He must begin his prison term Feb. 3.

“This was not a single act of bribery,” Messitte said. “This was not a single misstep. . . . This was a deliberate march down a long path of kleptocracy.”

Johnson’s sentence is among the longest historically for a Maryland politician in a corruption case. He asked that he serve his time in North Carolina at Butner, a federal prison in the Research Triangle area near Raleigh. Bernard Madoff, who is serving a 150-year sentence for running the largest Ponzi scheme in history, is housed at Butner, a sprawling medium- and low-security facility with a medical center.

Prosecutors and the judge indicated that Johnson has cooperated with federal authorities in their investigation of corruption in Prince George’s, resulting in the reduced sentence.

Johnson, who walked into court with the aid of a cane, tried unsuccessfully last month to get his sentencing date postponed a second time, arguing that he suffers from depression and Parkinson’s disease, a degenerative disorder of the central nervous system. His sentencing originally was scheduled for September.

At Tuesday’s hearing, Johnson and his attorneys asked the judge for compassion, arguing that doctors say he may have a rare form of Parkinson’s and that he appears to be “going downhill relatively quickly.”

“To sentence Mr. Johnson to many years in [prison] is a death sentence for him,” defense attorney Jeffrey Harding said. “He would go off to a federal penitentiary and die.”

But prosecutors said that in July, a week after Johnson’s diagnosis of tremors, the FBI showed photographs of him playing 18 holes of golf, carrying a golf bag and shaking hands.

“Clearly, he was capable of carrying his own bag,” Assistant U.S. Attorney James A. Crowell said.

Messitte said that officials from the Bureau of Prisons have reviewed Johnson’s health records and found that they are equipped to handle his medical problems.

Johnson, who was county executive from 2002 to December 2010, was charged 13 months ago with evidence tampering and destruction of evidence after federal agents arrested him and his wife, Leslie, 60, at their Mitchellville home. They were overheard on a wiretap plotting to stash $79,600 in cash in her underwear and flush a $100,000 check that he got as a bribe down the toilet. He also was videotaped taking cash bribes.

The Johnsons’ arrest last year roiled county government, ensnared several developers and public officials, and led to ongoing ethics reform.

Prosecutors said in court Tuesday that those paying the bribes to Johnson and other county officials as part of the conspiracy received more than $10 million in benefits in return. “Jack Johnson could have been a role model for integrity, but he chose to be a poster child for greed,” said U.S. Attorney Rod J. Rosenstein.

Hours after his arrest, Johnson announced that he was “innocent of these charges” and was “absolutely convinced” that he would be cleared. He pleaded guilty in May to extortion and to witness and evidence tampering.

Leslie Johnson (D), who was elected to the County Council 10 days before her arrest, will be sentenced Friday for her role in the extortion scheme. She pleaded guilty in June to one felony count of conspiracy to commit witness and evidence tampering and faces up to 18 months in federal prison. She did not attend her husband’s sentencing, but one of their two sons was there.

Meanwhile, at Tuesday’s hearing, a bespectacled Johnson appeared thin and balding and relied on a cane to keep him steady in his eight-minute statement. He recited a list of accomplishments during his eight years as county executive and pleaded with the judge to consider his good deeds.

“I worked so hard for the people of Prince George’s County, and I achieved so much,” he said, adding that he handed out 127 student scholarships and shipped medical supplies to Africa.

Messitte agreed that Johnson did “some good things,” but the judge showed little sympathy.

“You’re supposed to do all these good things,” Messitte said. “That’s what you were elected to do. You were not elected to line your pockets.

“Let’s be clear on who brought that on,” the judge said. “I did not. The government did not. You, Mr. Johnson, brought that on.”

Tuesday’s hearing brought to a close what had all the makings of a storied career. Johnson was sworn in nine years ago as only the second black person to hold the office of county executive in Prince George’s. As the former state’s attorney, Johnson was among the first wave of African American politicians to take control of Maryland’s second-largest county, which had been historically white and blue-collar but is now middle-class and largely black.

He cast an image of success and affluence that his supporters wanted to portray to the world. In many ways, he succeeded. Johnson lured Wegmans — the county’s first high-end grocery store — to the area and led Prince George’s during completion of the $2 billion, 300-acre National Harbor project nestled on the banks of the Potomac River, which includes a convention center, restaurants and retail.

Although Johnson was quick to take credit for improvements and growth in the county, he was just as swift in defending his questionable actions, which dogged him throughout his second term.

In August 2006, an investigation by The Washington Post found that he had awarded 51 county contracts totaling more than $3 million to 15 friends and supporters. In some instances, he gave the contracts after failing to persuade the County Council to put those supporters into county jobs. He also created more than a dozen high-profile positions and filled them with friends and fraternity brothers. Some of those who received contracts or jobs had no expertise in the field, and others did not produce written reports required by the county.

The Post also found that Johnson — and council members — charged thousands of dollars to county-issued credit cards to pay for personal expenses, violating county policy. Johnson’s charges included trips home to South Carolina, to visit his mother; to Texas, to attend his daughter’s wedding reception; and a $6,003 business-class trip to Senegal, for a ribbon-cutting ceremony for homes built by a county developer.