Collection consists of personal and business papers of John S.M. Neill, his wife Margaret G. Neill, and son George G.E. Neill. There are several business subgroups. The John S.M. Neill Subgroup consists of eight series: Incoming Correspondence and Outgoing Correspondence (1891-1912), both arranged chronologically; Miscellaneous Correspondence (1900, 1908), arranged chronologically; Financial Records (1889-1912), including a ledger, a journal, tax records, and other materials; Legal Documents (1886-1906), including documents of the Capital City Improvement Company and miscellaneous deeds and leases; Subject Files (1889-1912) concerning various real estate and mining properties, the Democratic Party, and the State Capitol site and building; Miscellany, including Helena real estate lot books, a personal memo book, and drawings for the State Fair Grounds Boulevard and other properties; and two scrapbooks of Clippings (1889-1890) concerning Helena real estate and politics. The John S.M. Neill Estate Subgroup consists of real estate assessment lists (1912) and a petition (1912) by the Collins Land Company to the City of Helena. The Margaret G. Neill Subgroup consists of eight series: General Correspondence (1905-1943) arranged chronologically; Court Papers consisting of a case (1939-1941) against Jacob P. Nordby; minor Financial Records (1895-1941); Legal Documents (1912, 1914); Speeches concerning her Red Cross work; Subject Files (1909-1928) concerning the World War I Liberty Loan drive and Helena real estate; Miscellany, including a minute book (1895-1898) for the First Presbyterian Church Helping Hand Society, and a financial journal (1914-1919) for the Presbyterian Church Ladies Aid Society; and Clippings (1918) concerning Red Cross war work. The George G.E. Neill Subgroup contains nine series: Incoming Correspondence and Outgoing Correspondence (1911-1960) arranged chronologically; Miscellaneous Correspondence (1911-1952, undated); Court Papers (1919-1949); minor Financial Records (1908-1953); Legal Documents (1913-1940); Subject Files (1908-1922) concerning the Barnes-King Development Company and the State Fair Grounds; Miscellany, including drawings for various buildings, a list of patented mining claims in the Helena Mining District, and a list of property ownership in the vicinity of Holter Dam; and Clippings about the Gallatin County Development Association and Democratic politics. There are small personal subgroups for Elisha S. Clark and for George Evans. The Elisha S. Clark Subgroup consists of invoices, including his estate (1887-1896). The George Evans Subgroup consists of legal documents (1888-1892) from the Harriet B. Miles estate. The Independent Investment Company Subgroup records include: Incoming Correspondence (1914, 1918); minor Financial Records (1904-1928); Legal Documents (1904-1928), including an abstract of title for the Independent building; and a minute book (1906-1916). The Independent Publishing Company Subgroup records include: General Correspondence (1904-1926); Court Papers regarding a case (1899) involving Fred Whiteside; minor Financial Records (1906-1934); Legal Documents (1901-1917); a Subject File (1892-1907) concerning the state printing contract; and Miscellany (1913-1926, undated), including Cass Gilbert drawings for planned additions to the Independent's building. The Lewis and Clarke County Democratic Central Committee Subgroup consists of two poll books (undated) listing registered Democrats in each ward of Helena and each community in the county. Records in the Madison River Improvement Company Subgroup include General Correspondence (1910-1950); Financial Records consisting of tax records (1919-1937); and Miscellany (1909-1937, undated), including a deed (1920) for land along the Madison River and sketch maps. The Montana Outdoor Advertising Company Subgroup includes General Correspondence (1927-1961); Financial Records consisting of summaries (1952-1958); and Miscellany (1929, 1957), including lists of billboard locations and a charter for the Outdoor Advertising Association of Montana. Records in the Montana Properties Company Subgroup include General Correspondence (1917-1947); Court Papers (1939-1941) regarding a suit by the City of Helena; and Legal Documents consisting of deeds (1921, 1925). The Montana Rapid Transit Company Subgroup records include General Correspondence (1908-1921); Employment Records consisting of payrolls (1909); Financial Records, including financial summaries (1910), a ledger (1909-1922), transcripts of books (1909-1913), trial balances (1909-1921), and tax records (1909-1925); Legal Documents (1908-1940); Organizational Records, including record books (1909-1924), annual statements (1910-1922), and other materials; Printed Materials consisting of a brochure (circa 1909) about the company; and Miscellany, including drawings of the planned route of the railroad through Helena and East Helena.