Chapman’s father, who had been knighted in 1780, succeeded by special remainder in 1810 to the baronetcy and Westmeath estates of his brother Benjamin, Member of the Irish Parliament for Fore, 1772-6, and county Westmeath, 1776-83. A figure from whom challengers had solicited support against the dominant county interests, on the death of the sitting Member in 1824 he successfully put up Robert Smyth, son of a former Member, allegedly as ‘a sort of locum tenens for the county, until his son came of age’. He proposed his re-election in 1826, when Smyth was defeated by a candidate backed by the Catholic Association.
At the ensuing general election he stood as an ‘uncompromising advocate for reform’ and was returned unopposed.
Chapman was absent from the division on the second reading of the revised reform bill, 17 Dec. 1831, but voted to go into committee on it, 20 Jan. 1832, and again supported its details. He attended a ‘respectable’ county meeting to draw up a favourable petition, which he presented, 9 Mar. He divided for the third reading, 22 Mar., but was absent from the division on the motion for an address calling on the king to appoint only ministers who would carry reform unimpaired, 10 May. He voted for the second reading of the Irish bill, 25 May, but was in the minority for Daniel O’Connell’s motion to extend the county franchise to £5 freeholders, 18 June. He divided against the liability of electors to pay municipal taxes before they could vote, 29 June, and argued for additional polling places to be provided at the ‘sessions-towns’ of large Irish counties, 6, 18 July. He voted with ministers on the Russian-Dutch loan, 26 Jan., 12, 16 and (as a pair) 20 July, and relations with Portugal, 9 Feb. He denied that a Westmeath petition against the new plan of Irish education expressed the sentiments of his constituents and hoped ministers would ‘carry the object they have in view’, 26 Jan., and asked why, if the Catholics did not object to it, it should ‘be opposed by the Protestants’, 13 Feb. He presented a hostile petition from the Presbyterians, 10 Apr. He argued against using force to ‘crush the combination against tithes’, 9 Feb., presented Westmeath petitions for their abolition that day, 9 Mar., 27 July, and voted to print the Woollen Grange abolition petition, 16 Feb. He divided against the tithes bill, 8, 27, 30 Mar., 6 Apr., 13, 24 July, but on 9 Apr. was one of the Members ‘usually opposing ministers’ on it who supported Crampton’s amendment concerning payment of arrears. He denied that Westmeath was in a state of ‘gross insubordination’, saying that there had only been ‘a few instances of outrage’, and took issue with the magistrates who had petitioned for an additional force, 15 Mar. He hoped that public opinion now had ‘sufficient control over this government’ to prevent them from pursuing a ‘wrong system’ on tithes, 28 Mar., and praised ministers for not deploying extra troops, 31 Mar. He divided for the navy civil departments bill, 6 Apr. He presented a petition for abolishing the death sentence for offences against property without personal violence, 25 May. He divided against Alexander Baring’s bill to exclude insolvent debtors from Parliament, 6 June. He was appointed to the select committee on Irish disturbances, 15 June. He condemned the ‘vague and indefinite’ Irish poor relief bill and was in the minority for permanent provision for the poor by a tax on absentee landlords, 19 June. He contended that the tithes bill had ‘failed already in those parishes where it has existed’, 13 July, and protested that ‘if government really wished to bring in a bill to set all Ireland in a flame, they could not have taken a more efficient course than they have done’, 27 July 1832.
At the 1832 general election Chapman successfully contested Westmeath as a Liberal. He was a founding member of the Reform Registry Association established in Dublin in 1836 and on its refoundation in 1839 became its chairman.
