The Stephen G. and Ann Maria Wheatland papers contain mostly financial papers, as well as papers from Stephen's administration of estates, some correspondence, and personal papers. This collection has been divided into four series.

Series I. Estate Administration contains materials concerning the administration of a number of individuals' estates, including Stephen G. Wheatland. Stephen appears to have been an administrator or trustee for a few different estates, including those of Captain Timothy Bryant, Robert E. Bemis, and Martha Bemis. This series has been divided into four subseries. Subseries A. Timothy Bryant contains materials from Stephen Wheatland's trusteeship of Captain Timothy Bryant's (1787-1870) estate. Stephen's father was a ship master on some of Bryant's ships. Subseries B. Bemis contains materials from Stephen Wheatland's management of the Bemis family estate. It appears that Stephen's brother in-law, David Pingree (1841-1932) took over the management of the Bemis estate after Stephen's death, as some of the later estate correspondence is addressed to him. Subseries C. Other contains materials from Stephen's management of other individuals' estates. Subseries D. contains materials relating to the administration of Stephen's estate after his death.

Series II. Financial contains financial papers from Stephen G. Wheatland and his family; this series has been divided into four subseries. Subseries A. Checks Returned contains checks written by Stephen or on his behalf that were returned back to him after they were cashed. Also included in this subseries are check books with check stubs in them. Subseries B. Paid Bills contains bills for either Stephen or his family. The paid bills are organized according to the date on which they were paid, if that date is marked on the bill. If the date is not marked on the bill, the bill is filed according to the date on which it was created. Subseries C. Account Books contains family accounts and bank books. Subseries D. Other Financial and Business Records contains some materials relating to real estate that the Wheatlands and/or Pingrees were involved in, such as receipts, payments, and deeds. This subseries also contains some miscellaneous accounts.

Series III. Correspondence contains correspondence to and from the Wheatlands. The correspondence, while not a large portion of the collection, is mostly personal in nature. Correspondents include friends, family, and some business associates. Much of the correspondence from 1892 is condolences sent to Stephen's family after his death. Also included in this series are public addresses made by Stephen.

Series IV. Other contains miscellaneous family papers, such as George Wheatland's college expenses and Stephen Wheatland's report card from Harvard University, as well as his notary public certificates and passport. Also included in this series are different obituaries for Stephen Wheatland, some news clippings, and miscellaneous materials.