Since 1873, the librarians, who have succeeded one another in the direction of the Angelica Library, have taken care to increase its holdings by privileging those fields that have characterized it since its origins: Augustinian studies, Italian literature and literary criticism in the 15th-18th centuries, theater history, Reformation and Counter-Reformation, Romanesque, opera librettos and Bodonian editions.

In nearly a century and a half, the holdings have increased by about another 100,000 volumes of Italian and foreign editions and bibliographic aids in both print and electronic media.

In the last century, between 1944 and 1952, Francesco Barberi worked to acquire ten volumes of the autographs of
Luigi Zanazzo
, containing unpublished compositions and collections of proverbs from plays and Romanesque songs.
He also received the donation of documents of the poetic and literary activity of
Domenico Gnoli
(1838-1915) and the correspondence of archaeologist
Felice Barnabei
(1842-1922).

In 1975, the Angelica accepted the legacy of literary critic
Arnaldo Bocelli
: a library of 8,600 works including texts, essays and journals related to 20th-century Italian literature.
Also of note in the 20th century are the fund belonging to the family
Marcello Cardone
and the fund of
Achille Tartaro
.