Because the board of directors and superintendents of the corporation often acted in similar capacities and generated the same types of records, these documents are filed together. The superintendent (originally called the agent) reported to the board of directors and ran the day-to-day operations of the company. He also often served as the corporation's treasurer.

Included in these records are correspondence; reports to the directors and shareholders by superintendents, treasurers, and committees; building and service contracts; petitions; applications; bonds; agreements relating to land and water rights; resignations of agents, presidents, and board members; property lists; correspondence with Boston selectmen and later the Boston City Council; notices of board meetings; proposals; and building specifications.

Superintendents' reports to the board and stockholders contain particularly detailed information, describing construction activities, problems and successes, expenses, and plans. Early superintendent's reports are referred to as treasurer's and agent's reports, and also include financial data. Also in this series are applications for the position of toll gatherer (1821); writs of attachment and other legal documents; surety bonds for treasurers and toll gatherers; a series of proposals to fill old sluices (1834-1835); a proposal to build a sea wall along Western Ave., later known as Beacon St. (1840); building specifications for houses on Western Ave. (1848); and records of the corporation's Back Bay Commission committee (1852).

Notable board members include John Lowell, Ralph Huntington, Harrison Gray Otis, and Artemas Ward. Superintendents whose records are included in this series include Uriah Cotting, who served from 1817 to 1819; Loammi Baldwin, from 1819 to 1822; Samuel Nicolson, from 1827 to 1855; and William S. Whitwell, from 1855 to 1887.

Volumes in this series include six directors' record books, spanning the years 1823-1912, which contain meeting minutes, indentures, reports, bylaws, committee reports, results of surveys, copies of agreements and contracts, and copies of plans. Shareholders' meeting minutes appear at the back of each volume. A letterbook contains copies of the correspondence of superintendents William S. Whitwell and William Matchlett from 1859 to 1891, and includes an index.

Records in this series that are dated earlier than 1818 are copies or abstracts of earlier deeds related to Boston and Roxbury Mill Corp. lands. Deeds held directly by the corporation date from 1818. This series also includes leases and indentures held by the corporation.

By 1854, the corporation began to lease and sell their lands in the Back Bay, specifically on Western Ave. (later known as Beacon St.), and the deeds found here pertain to these transactions. The series also includes indentures between the corporation and the city of Boston, as well as the commissioners of public lands.

The Book of Deeds contains handwritten copies of deeds pertaining to the corporation, as well as several original deeds pasted into the volume.

This series contains lists of measurements, estimates, and other memoranda and accounts related to building projects conducted by the corporation. Included are an 1814 account of tides at the South Boston Bridge, measurements for buildings, distances between points of land, measurements for stones and iron posts, memos of articles delivered and received, estimates and certifications for land fill (1850s-1860s), paving stones delivered to the mill dam (1880s), and other accounts relating to building dams, walls, fences, land fill, and paving stones.

Scow memoranda relate to the scows, or open barges, hired by the corporation to haul loads of mud or ballast for landfill, and include the name of the owner or skipper, the scow's identification number, and the number of loads it carried per month.

In February 1818, Joseph Chesley III of Durham, N.H. contracted with the corporation to build three scows and deliver them to Boston. Later, the corporation hired Chesley to break out and deliver 10,000 perches of stone for walls, paying part of the contracted amount to Chesley in advance. In August 1818, the corporation issued writs of attachment related to Chesley's non-performance of contract, suing him in November 1818.

In March 1820, Chesley countersued the corporation for back wages. Depositions in this series pertain to the 1820 trial. Other records include writs of attachment, correspondence, accounts and receipts, undated memos, and superintendent Loammi Baldwin's case notes.

Included here are the corporation's accounts with individual agents, balance sheets, disbursements, quarterly and monthly statements, trial balances and ledgers listing receipts and expenditures. Early records (1818-1821), which comprise the bulk of this series, largely consist of expense reports from project managers Charles Blaney, Enoch Moody, and Amos Cotting, including labor and materials. Beginning in 1831, the series also includes monthly treasurer's accounts and annual reports presented to corporate stockholders.

Journals and daybooks record the sequential daily account of all financial transactions. Ledgers list accounts by person, firm or product, including tolls, house rents, land rents, road expenses, house expenses, iron work and hardware, notes payable and receivable, interest, stock, stables, toll houses, salaries, boat houses, bathing houses, profit and loss statements, and balance statements. Cash books record all cash payments and receipts, including bills, labor (but not payroll accounts), dividend payments, salaries, and building materials.

Records in this series include both loose records and several softbound account books, the bulk of which date from 1818 to 1821. Loose payroll records are recorded by week, and include the name of the worker, number of days per week he has worked, daily wages, total wages for the week, and the worker's signature verifying that he has received his pay. Most payrolls also list the occupation or work description of the laborer. Some 1820 payroll records list over 200 men per week. Between 1824 and 1855, payroll records consist only of individual receipts for wages. Later records (1855-1863) include both laborers and tollmen.

This series includes two volumes listing daily receipts for tolls collected on the corporation's road. Originally known as Mill Dam Rd., it later became Western Ave. and, in 1865, Beacon St. The first volume contains lists of receipts for tolls collected by James Willson from July 1821 through March 1823, recorded by treasurer Samuel McCleary. The second book contains receipts for tolls collected from January 1835 through December 1849, recorded by treasurer Samuel Nicolson.

Beginning about 1850, the corporation began constructing houses and other structures on their land to rent to tenants. Rent books list renters, date rent is paid, and the amount of rent for structures, including the Old Toll House, Tavern Estate, Store and House on the Wharf, and Houses #1-5. The later two rent books are organized as ledgers, with accounts listed by renters' names.

Bills and receipts reflect the general activities of the corporation. These transactions were usually also recorded in the treasurers' cash books and ledgers. Most of the bills and receipts are individual receipts for services such as advertising, printing, general labor, stone splitting, transportation, construction contracts, carpentry, legal expenses, and water. Receipts for supplies include nails, gunpowder, groceries, rum, cordage, timber, ballast, hay, cast steel, office supplies, coal, oil, and materials for constructing houses, such as wallpaper and window sashes.

This subseries is stored offsite and must be requested by barcode at least two business days in advance.

This series includes promissory and bank notes signed by the treasurer to various banks, insurance companies, and individuals, using shares of stocks and bonds as collateral. The values of the notes range from $300 to $30,000, with the bulk dating from 1860-1865. The bound volumes entitled "Notes and Bills Payable and Receivable" list the date of the note, from whom it was received, the amount, length of loan, date due, and the endorsers.

This series includes fire insurance policies purchased by the corporation for the buildings and structures that they owned. They describe the property, its location, and its usage, as well as the property's value. In 1829, a policy for $13,000 included the "building and fixtures of City Mill for grinding grain and on four blocks of wooden buildings on the easterly side of the mill." In 1831, a $5,500 policy for a tavern house and stables was added. By 1847, insured property included a sawmill and machinery; a machine, forge, and pattern shop; a foundry; a boiler house; a blacksmith shop; a locomotive shop; and a mill for sawing mahogany, as well as all tools, machinery, and other contents. In 1850, the corporation began to insure the dwelling houses they were renting to tenants.

This series includes individual checks written by the corporation's treasurer, the bulk of which date from 1818-1821. A check register dating from 1891-1898 lists the check numbers, payees, and amount of payment.

These records include lists, accounts, and memoranda related to various financial topics. The bulk are short memos dating from 1875 to 1886 written by superintendent William Matchlett in regard to dividends, indentures, cash settlements, and other financial matters.

This series primarily consists of letters to the corporation's treasurer requesting dividends to be paid, inquiring about dividends, or authorizing powers of attorney for proxies to vote at the annual stockholders' meeting.

Loose records include alphabetical lists of stockholders from the years 1818, 1831 through 1857, which include only the stockholders' names and the number of shares owned. The bulk of the records, however, date from 1871-1891 and are printed with stockholders' names and place of residence, as well as the number of shares owned. They date from May of each year.

Volumes in this subseries include a shareholders' record book which contains alphabetical lists of stockholders in February 1818, December 1819, December 1820, and July 1832, as well as all transactions related to the sale and transfer of stock from 1818 to 1856. Beginning in 1835, the number of the stock certificate is also included. The shares book also covers the years 1818 to 1856, but it is organized alphabetically, listing shares held by each stockholder with an index in the front. The list of stock certificates contains the number, name of the original buyer, and subsequent owners from 1818 to 1835. The record of stockholders dates from 1849 to 1858 and contains an alphabetical list of stockholders with the number of shares they own for each year.

The bulk of this series is stock certificates originally issued between 1818-1901 that were returned to the corporation when it bought back the shares. They contain the name of the stockholder, number of shares, certificate number, and signature of the board president and treasurer. Information on the verso records the subsequent sale or transfer of the stock. Certificates are filed alphabetically under family name. Also included here is correspondence related to lost certificates or requests for a duplicate certificate, as well as probate court records certifying the estate settlements of deceased stockholders.

This subseries is stored offsite and must be requested by barcode at least two business days in advance.

These five books list each dividend paid by the corporation and contain the name of stockholders, the amount of each dividend, dates, and signatures of stockholders verifying their receipt of the dividend. Together, they create a fairly complete record of stockholders, except for a gap during the years 1865-1867.

The bulk of Whitwell's correspondence are letters to and from his brother-in-law, William Parker, in relation to Whitwell's candidacy for superintendent of the New Jersey Railroad and Transportation Co. in Jersey City, N.J. Also included is correspondence with his sister Lucy Cushing Parker, his son William S. Whitwell, Jr., other family members, and business associates.

Personal bills and receipts include those for groceries and sundries, medical fees, clothing, household furnishings, tuition, gas and water bills, rent and tax payments, home repairs, and other expenses.