In Barr’s case, the email records show that executives from the company asked Mr. Kaine to intervene with the Food and Drug Administration on its behalf in August 2006, just days before the flight to Aspen for a meeting of the Democratic Governors Association, later valued at $12,000 in Mr. Kaine’s disclosure report.

Mr. Kaine signed the letter to the F.D.A. — a draft of which had been written by Barr — as requested before leaving on the trip, and a company lobbyist suggested that he was prepared to follow up during the plane ride.

“The Gov will be on a plane on Friday with Phil Smith,” Eileen Filler-Corn, an aide to the governor, wrote in an August 2006 email, after she had met with Mr. Smith, then a lobbyist from Barr. “Phil will likely speak with to Gov about him sending a letter in support of the petition in Aspen this weekend, hence this email to ya’ll.”

State records compiled by the Virginia Public Access Project show that a total of 139 companies or individuals gave about 220 gifts or reimbursements for travel to Mr. Kaine to work-related conferences while he served as governor from 2006 to 2010 and lieutenant governor from 2002 to 2006. Amy Dudley, a spokeswoman for Mr. Kaine, said that two-thirds of the filings were in the work-related travel category, and that Mr. Kaine was careful to disclose any gift, even if it was from a family friend, which is not required under the law.

She rejected any suggestion that Mr. Kaine may have done anything to benefit any individual or company that had given him a gift, including Teva, which sells generic drugs and has a large manufacturing plant in Forest, Va.

“Many governors at the time believed, as then-Governor Kaine did, that more widespread use of generic drugs would reduce state and federal health care costs without compromising the quality of care,” Ms. Dudley said.

The issue of gifts to elected officials has become particularly delicate in Virginia in the aftermath of the criminal case against Mr. Kaine’s successor, Bob McDonnell, which was filed in 2014, even though his conviction was vacated late last month by the United States Supreme Court. Mr. McDonnell took much more extravagant gifts — including a Rolex watch and catering for his daughter’s wedding and other gifts and loans worth $177,000 — from a single businessman who was seeking help with a state government-related matter, and Mr. McDonnell did not disclose all of those gifts.