Since he arrived in 2011, James A. Jackson has pushed for change in the Richmond Department of Public Works.

Instead of top-down leadership, he has spearheaded a team approach, worked to replaced outdated equipment and sought to address the backlog of citizen complaints about services.

Evidence of his leadership can be seen in the city’s stepped up efforts to patch streets, prune trees, collect refuse, mow grass and improve alleys and the increased satisfaction levels residents express about city services.

On his watch, the city has developed an assessment of streets to provide a priority list for repaving and inventoried the trees on city property to improve management. There is now an accurate inventory of the city’s fleet, and a clear plan for maintaining and replacing equipment.

In the coming months, new initiatives he has pursued will enable the city to use energy savings to fund millions of dollars in needed renovations to fire stations and other city buildings and expand recycling to cut the amount of trash the city sends to landfills.

As a result, Mr. Jackson, an enthusiastic man with a quick smile, seemed entrenched in his position.

So his abrupt resignation last week from his $137,000-a-year job came as a surprise.

His boss, Christopher Beschler, deputy chief administrative officer for operations, accepted Mr. Jackson’s resignation effective May 27, one day after he submitted it.

Mr. Beschler and Selena Cuffee-Glenn, Richmond’s chief administrative officer, declined to comment, citing the city policy of not commenting on personnel matters.

However, according to documents Mr. Jackson provided to the Free Press, he quit after Mr. Beschler and Ms. Cuffee-Glenn would not allow him to attend a prestigious, three-week summer management course for state and local government officials at Harvard University.

“I was ready to pay for it myself,” Mr. Jackson said, adding that he could not get approval to use his vacation time to attend the course he believed would assist him in being a better manager.

He said as a result of the delays and his resignation, Harvard rescinded its invitation with encouragement that he reapply “when my organization supported my attendance.”

The saga began in early April when he notified Mr. Beschler, then serving as interim CAO, that he was among 70 state and local officials Harvard had accepted for the course from about 2,500 applicants.

Mr. Jackson said Mr. Beschler kept dragging his feet about allowing him to attend. Mr. Jackson said all he got from Mr. Beschler were repeated promises that the city would pick up the $12,400 tab for the course and give Mr. Jackson a leave of absence so he would not need to use vacation time.

In a May 12 email to Mr. Jackson, Mr. Beschler again promised to get an invoice signed to cover the tuition for the July session at Harvard. But Mr. Jackson said that promise was never kept before Ms. Cuffee-Glenn took over as CAO on May 18.

The final straw, Mr. Jackson said, came a few days later when he received a call May 22 from Ms. Cuffee-Glenn while he was in Kansas City attending the memorial service for his father-in-law.

He said Ms. Cuffee-Glenn offered condolences but said she could not approve his request to attend the Harvard course because she would need time to review his department’s operations.

Mr. Jackson said she promised to get back to him after he asked if he could use his vacation time to attend.

However, when he hadn’t heard anything from her by May 26, he came to the conclusion that she wouldn’t conduct her review in a timeframe that would allow him to attend the course.

“With no further recourse, I submitted my letter of resignation” from the department, he said.

Harvard rescinded its invitation to him after he resigned from his job.

“This is not a busy time of the year for my department. I thought the administration would be happy” that he was trying to improve himself.

Instead, he said he could not get any support.

Mr. Jackson said he and his wife, Saundra, have been happy in Richmond, and he had hopes he would be able to continue as director after the next mayor is elected in 2016.

In the end, “I could not trust the administration,” Mr. Jackson said.