There is a wealth of information in historical societies, from large old state collections, such as Marylandís, started in 1844, to a one room local county. The oldest, founded in 1791, is the Massachusetts Historical Society. The Pennsylvania Historical Society has been collecting items since 1824, (conveniently located next to the Library Company of Philadelphia) and possesses the original Custis cookery book owned by Martha Washington, which was transcribed into Martha Washington Book of Cookery.
Handwritten manuscripts, letters, store records, newspapers, city directories, pictures, genealogy and more sources of information are found at large and small historical societies. Many of the larger historical societies have started putting their catalogs online, so you can do some of your prep work ahead of time. The Historical Society of Delaware Library even has evening hours. Although the days and hours of the smaller ones may be listed, call ahead to make sure a volunteer will be there and it will be open. Whether you travel across country or just two hours away, be sure to ask if they have published any of their works, to save you time in typing/writing. An online listing of the PA and MD local societies is on their state Archives websites.
Most museums contain a library available to the public. It may be one room in a small local museum or a large collection of books and manuscripts. Generally anyone may research their holdings, although a couple, the Folger (DC) and Huntington (CA) have restrictions.
Colonial Williamsburg has a two story library with a separate reading room for manuscripts, ledgers, rare books, etc. The Peabody Essex Museum library in Salem also contains manuscripts, ships journals and more in a centuries old building.
Occasionally, the library may not be in the facility. The Marinersí Museum in Newport News, VA no longer maintains their library in the one end of their building, but has moved it to the Christopher Newport University. The Smithsonian has numerous libraries in its various museums, and even separate buildings.
If you are interested in visiting a museum library and its museum check their website or call for hours and any restrictions. Most have limited hours and are closed on weekends.
State Archives & County Courthouses
Each state archives contains copies/original records from local courthouses and other government agencies, but the years vary with each state and circumstances (such as fires). Although some of the archive buildings are still next to their state capitol - Pa. is just down the hill, the Md. Archives is a healthy walk to the oldest continually used State House, and others are miles away - Mass. is located across the parking lot from the JFK museum & library. The National Archives is now in two locations, DC and College Park, MD, but there are branches throughout the country, including Philadelphia.
Probate inventories. When a person died a record listing every item was made and filed in the courthouse, but like today, this was not done for every estate. It is a terrific resource for food historians. The inventory shows not only what items they owned for cooking and dining, but where it was kept. Often the list goes from room to room, although the rooms may or may not be labeled. Even if the person or museum house you are searching does not have one, you can search for other local comparable probate estates. Gunston Hall did such a search in the VA/MD area: http://chnm.gmu.edu/probateinventory/search.php
Genealogical research is helpful in learning more about the person [birth, death records, census] and thus useful in finding other sources of information. Knowing the relatives can help find more letters related to the person/home you are researching. Wills give details on the family, ofcourse, but may mention such things as outbuildings.
Recipes can be found in letters or written manuscripts which have been donated to the archives.
Other items found in the Archives may include property sales [which may list outbuildings, orchards, etc], Tax Lists, colonial newspapers, church records, manumission papers, colonial and state/county records, maps, plats, and much more.