He restructured the colony's Executive Council by including reformers in the body which had previously been a Tory domain but resisted the demand that the majority party in the legislature be permitted to form a government.

He then returned to England and held office in the Whig government of Lord John Russell as Captain of the Yeomen of the Guard from 1846 to 1848.

Lord Falkland married Lady Amelia FitzClarence (21 March 1807 – 2 July 1858 London), the last unmarried illegitimate daughter of King William IV and his mistress, Dorothy Jordan, on 27 December 1830 at the Royal Pavilion.

[8] They had one son, Lucius William Charles Frederick Cary, Master of Falkland (24 November 1831 – 6 August 1871), who married Sarah Christiana Keighly (d. 4 October 1902), but died childless.

As his only son had predeceased him, he was succeeded in his titles (except for the barony of Hunsdon) by his younger brother Admiral Plantagenet Pierrepont Cary.