Originally envisioned as a small network of libraries throughout the independent city of Brooklyn, the BPL system was approved by an Act of Legislature of the State of New York on May 1, 1892, and later passed by resolution of the Brooklyn Common Council on November 30, 1896.

In 1898, as Brooklyn was consolidated into the City of New York and became the Borough of Brooklyn, the tenure of the library's first director, Mary E. Craigie, came to a close. The development of the library system continued over time, with construction occurring as funds were raised. Building of the Central Library at Grand Army Plaza began in 1912, and was not completed until 1941. Between 1901 and 1923, however, much progress was made thanks to the generosity of the great philanthropist Andrew Carnegie, who donated $1.6 million toward the development of 21 branch libraries.

Today, the BPL system is the fifth largest library system in the nation, existing independently alongside the New York Public Library (serving the Bronx, Manhattan, and Staten Island) and the Queens Borough Public Library. Consisting of 58 branches located within a half mile of every Brooklyn resident, plus an outstanding business library in Brooklyn Heights and the only public bookmobile in New York City, the BPL system stands testament to the dedication of many generations of public servants.