BOSTON — The Boston Public Library has recruited an army of volunteers to help transcribe its extensive collection of 19th century anti-slavery documents.

The goal of the project launched last month is to make the roughly 12,000 pieces of correspondence from some of the era’s most prominent abolitionists more searchable and more accessible to both scholars and the general public. Already more than 2,200 volunteers have signed up for the project that could take a couple of years.

Much of the collection was donated to the library in the late 1890s by the family of prominent abolitionist William Lloyd Garrison. His donation, in turn, inspired others closely involved in the anti-slavery movement to donate their correspondence to the library.

Transcribing the documents isn’t easy.

The handwritten letters are sometimes difficult to read, and often use archaic wording and abbreviations.