To find NYC guidebooks in a foreign language:
The oldest Spanish-language guidebook appearing in the NYPL catalog is the Manual de Nueva York para uso de los Espa̜oles (1851), followed by Guia de Nueva York y los Estados Unidos in 1856. Also notable, Guida Manuale ad uso dell' Italiano in New York per l'Anno 1882 was a guidebook targeting the city’s growing Italian immigrant population. “After 1860, the number of Italian‐born persons in New York City came close to tripling every ten years: 3,017 in 1870; 13,411 in 1880; 49,514 in 1890; and 145,433 in 1900.” There are also a handful of 1800s guidebooks in German, the language of New York's largest first and second generation population at the time.