MANSFIELD, Mass. (AP) — In the office of Janet Campbell, hangs a black and white portrait of a smiling 16-year-old teenager dressed in a wool coat, book in hand, surrounded by a group of peers beside a bookmobile.

The photo was taken at the "Librarian for a Day" program in Wayne, N.J., and it was when Campbell decided she wanted to become a librarian more than 46 years ago.

Two years later, Campbell began what she calls her almost four-decade long term of library service, a journey that will soon be coming to an end.

Campbell will retire as library director at the Mansfield Public Library in March.

"It isn't an easy decision, and I thought I would be here forever," Campbell said. "But, change is good."

After earning an undergraduate degree in English from Bridgewater State College and a master's degree in library science at Simmons College, Campbell headed to Norton as the assistant director of the children's library for 13 years.

Then, she moved to Mansfield.

For the past 23 years, the Mansfield Public Library has become Campbell's second home.

"I was here when we were located in the cellar of the old building," Campbell said, referring to the current superintendent's building. "So, I've been fortunate enough to witness and be part of some of the library's major decision making."

Since 1987, when the library became the first in its consortion to introduce computers to customers, Campbell said advances in technology have continued to expand.

"I remember when we first offered Wi-Fi and online resources," she said. "Now we're providing full magazines and online classes on tablets and smart phones."

Though much of the library resources have gone digital and can be accessed online, Campbell said the library is bursting at the seams and further expansion may be necessary.

But, that's in the future.

Campbell said she often reflects on the many relationships she has formed with patrons over the years.

"Sometimes I have mothers bring their children in and tell them I was their librarian when they were children," she said. "This part of working here so long is the most rewarding because there is a sense of community."

Campbell says it's a community she will never forget or leave behind — even after retirement.

"I plan to stay involved and still come to some of the events here," she said.

Campbell also says she plans to catch up on adult fiction bestsellers, and aims to read a book each day.

"I enjoy television shows like NCIS and House, but I don't intend on extending TV watching," she said, pointing to a stack of colorful post-it notes inscribed with book titles. "I'd much prefer reading 300 pages."

Though sad to leave the library, Campbell says she's excited to open a new chapter in her life. One she hopes to fill with literature, travels and family.

"People don't stay forever, but I believe I was here for the exact amount of time I was needed to be," she said.