Rider also wrote quite a few art criticisms and many biographies, including one on Catherine R. (Arnold) Williams (1788–1872), a well-regarded poet and author who was intimately involved in the Dorr Rebellion.  His promotion of the work of a female author suggests something of Rider’s liberal qualities. Rider’s journal Historical Tracts brought many other biographies, historical episodes and documents to an interested readership in the latter half of the nineteenth century.    

Rider’s collecting habits transformed his shop into a time capsule of sorts; he stockpiled  everything from valuable manuscripts to the smallest vestiges of daily life, such as play bills, lottery tickets, and other paraphernalia. Consequently, Rider’s shop gained popularity as a gathering place for local bibliophiles and academics. In 1880, Brown University awarded Rider with an honorary Master of Arts degree for his ambitious and educational essays on Rhode Island history and culture. However, Rider also suffered his share of personal and financial difficulties from the 1880s to the 1890s.  In addition to the suicide of his brother in 1881 and the arrest of his son in 1893, Rider accumulated substantial debt, petitioned for bankruptcy, and was sued for loss of property.

In the early twentieth century, Rider finally surrendered to old age and retired.  In 1903, wealthy financier Marsden J. Perry purchased the Rider Collection and deeded it to Brown University. On January 17, 1917, Rider died and was interred at North Burial Ground, Providence, R.I.

Sidney Rider lived a full public life as an engaged citizen, merchant, critic, historian, writer, collector, reformer, and publisher. While his writings often centered on controversy and scuttlebutt, many of his contemporaries admired his erudite knowledge of Rhode Island history. Today, scholars and researchers are indebted to Rider for his meticulous collection of Rhode Island literary artifacts now housed at the John Hay Library.