Political papers, mostly relating to Churchill's three offices of state:
 Early, non-political correspondence and papers, 1840-77, including Churchill's Oxford University matriculation and examination certificates, 1840-42; Lord John Russell on the value of Church property, 1852; the offer of the Lord Lieutenancy of Oxfordshire by Lord Palmerston (3rd Viscount), 1857; the Prince of Wales on the new club in Pall Mall to be called the Marlborough Club, 1868 (4 letters); Lord Randolph Churchill's apology to the Prince of Wales, 1877; and letters from the 6th Duke of Marlborough (1851) and Sir Francis Knollys (1877).
 Lord Steward's department: correspondence, accounts and papers, 1866-67; Sir John Cowell on Household appointments. There are letters from Sir John C. Cowell (10, 1866-67) and Edward M. Browell, Board of Green Cloth (8, 1866).
 Lord President of the Council: correspondence, 1867-68, from the 3rd Duke of Buckingham and Chandos (1868); 15th Earl of Derby (7, 1866-68); Benjamin Disraeli (11, 1867-68); Charles T. Longley, Archbishop of Canterbury (2, 1868); 6th Earl of Mayo (1867) and 6th Duke of Richmond (1868) on education; and Queen Victoria, mostly concerning times of Privy Council meetings (7, 1867-68).
 Lord Lieutenant of Ireland, 1876-80, correspondence and papers: Duke of Abercorn on arrangements for Marlborough's succession and entry into Dublin; J.T. Ball, Lord Chancellor of Ireland, on Irish legal appointments and legal aspects of land meetings; Benjamin Disraeli (Lord Beaconsfield) on offers of Viceroyalty, the appointment of the Chief Secretary of Ireland to the Cabinet, appointments needing the Queen's approval, the Irish University Bill, and agrarian agitation; T.H. Burke, Under-Secretary, on county constabularies, disturbances and agitation, and the anti-rent movement; Lord Randolph Churchill about whether Marlborough should resign; Edward Gibson, Attorney-General, on Irish legal appointments; Lord Granard on a scheme for the Royal University of Ireland; Sir Michael Hicks-Beach, Chief Secretary, on legal and county appointments and University education; James Lowther, Chief Secretary, 1878-80, on legal and administrative appointments and University and primary education; Sir Stafford Northcote, Chancellor of the Exchequer, on government loans for public works; Lord Oranmore on crime and unrest; memoranda and reports on intermediate schools and the outrage at Tobertinan (attack on McEvoy), Co. Meath, 1880; printed reports from Resident Magistrates; papers on the renewal of the Peace Preservation (Ireland) Act 1875 for five years, 1880; and J. Ellis French, Detective Director, observations and statistics on agrarian crime, tenant right meetings, attacks on process-servers, and protection posts (1879).
The correspondents in this section include the 1st Duke of Abercorn (7, 1876); John Thomas Ball, Lord Chancellor of Ireland (12, 1878-80); Benjamin Disraeli, 1st Earl of Beaconsfield (49, 1874-80); Charles F. Bourke, Prisons Department (7, 1877-78); Sir John B. Burke (1876); Thomas Henry Burke, Under-Secretary (23, 1877-80); Lord Randolph Churchill ; Duke of Connaught (3, 1877-80); Montagu Corry, 1st Baron Rowton, Private Secretary to Lord Beaconsfield (5, 1876-80); Edward Gibson, 1st Baron Ashbourne, Attorney-General (11, 1878-80); 7th Earl of Granard (7, 1879); Sir Michael Hicks-Beach, Chief Secretary (13, 1876-80); James Lowther, Chief Secretary, 1878-80 (32, 1878-80); Sir Stafford Northcote, Chancellor of the Exchequer (1880); the O'Conor Don (1879); 2nd Baron Oranmore (3, 1877-78); and Bartholomew Woodlock, Catholic University of Ireland (1879).