Bill jackets are the most common and often the most informative type of New York State legislative history material. Physically, they are manila folders with whatever documents were gathered together and sent to the Governor by the legislature to assist his consideration of whether to sign or veto a bill. Bill jackets are generally available starting in 1921 (although a few are available from 1905). In most cases, they include:
(1) The version of the bill passed by the Senate and Assembly (often missing);
(2) Senate and House Yea and Nae (i.e., voting) records (sometimes missing);
(3) The bill sponsor's memorandum.
In addition, bill files often include "Solicitation of Opinions" materials -- memos about the legislation from state agencies or departments, and letters from outside parties (ex. bar associations, labor unions). They may also contain the governor's approval memorandum or the governor's recommendation to the General Assembly about the bill.
On the other hand, bill jackets sometimes contain little more than a copy of the bill. There is generally no way to know the contents of a bill jacket until you see it.
For more information, see the What is legislative intent? by the New York Legislative service and/or Bill, Veto and Recall Jackets by the New York State Library.
Getting Bill Jackets: Leading sources for bill jackets include ...
(a) The New York State Archives' Digital Collections, which posts bill jackets in PDF format from free covering 1997 to about two legislative sessions back.
(b) Westlaw (NY-LH-BILLJACKET), which has Bill Jackets from 1996 to 2006.
(c) The NY Legislative Service (212.962.2826 or -2827 or -2828). NYLS can often augment bill files with reports, debate transcripts, hearing transcripts, newspaper clippings and other materials that are useful for determining legislative intent. If you want more than the basics, NYLS is the way to go.
(d) NYPL Premium Services, which sells copies of older bill jackets for a reasonable price (212-592-7201). To order, you'll need the year {L.} and chapter number {c.} of the bill.
(e) The New York State Library, which has bill jackets from 1921 to at least 2006, plus 1905 (518-474-5355).
(f) The New York State Archives (518-474-8955).
(g) Zapp Couriers (518-449-3361). I have used Zapp to get copies of recent bill jackets from the legislature.
(h) In a pinch, the Legislative Secretary to the Governor's Counsel (518-474-7182) may be able to help you get recent bill jackets.