New York State legislative materials available are limited; little is published and disseminated. The primary, and often only, source for New York State legislative history at NYPL is the Legislative Bill Jacket, which contains a miscellany of documents, most importantly the Sponsor's Memorandum.
See more discussion of Bill Jackets at NYPL here.
Bill Jackets are keyed to session laws, cited by year and chapter number (e.g. L.1993, c. 662). If you are working from a code citation (McKinney's Consolidated Laws), see "Credits" or "History Note" at the end of the code section, which will cite the session law establishing the law, and any subsequent amendments. From WestLaw:
Once the session law citation has been determined, you can obtain the Bill Jacket by year. They are kept at the library on microfilm, microfiche, or CD-ROM, depending on year, and can be requested in the Main Reading Room.
|1905, 1921 - 58||*ZAN-T654 [Microfilm]|
|1959 - 74*||*XLE-318 [Microfiche]|
|1975 - 82||*ZAN-T654 [Microfilm]|
|1983 - 2001||*XLE-318 [Microfiche]|
Bill Jackets between 1905 and 1921 were destroyed in a fire, and are not available. Bill Jackets for the following are also not available:
1959, chap 651
1960, chap. 23, 864
1961, chap. 429, 431-450
1965, chap. 160-161, 163, 167-175, 396-397, 572, 593, 636, 721, 742, 896, 905
1966, chap. 71, 98, 99, 206, 274
1967, chap. 559, 771 (part), 790, 798 (part)
1972, chap. 837
1973, chap. 11?
1974, chap. 62
The sponsor's memorandum and the Governor's approval memorandum can also be found in McKinney's Session Laws of New York (see below) and the New York State Legislative Annual.
When a bill is passed by the legislature and signed by the Governor, it is published as a "session law," and is cited by year and chapter number (as discussed above). You may need to consult New York State session laws to read the legislation as passed, or see amendments and track changes to a law.