Spring Rice's grandfather, Edward, had converted the family from Roman Catholicism to the Anglican Church of Ireland, to save his estate from passing in gavelkind.

He positioned himself as a moderate unionist reformer who opposed the radical nationalist politics of Daniel O'Connell, and became known for his expertise on Irish and economic affairs.

[6] Spring Rice's fluent debating style in the Commons brought him to the attention of leading Whigs and he came under the patronage of the Marquess of Lansdowne.

As a result, Spring Rice was made Under-Secretary of State for the Home Department under George Canning and Lord Goderich in 1827, with responsibility for Irish affairs.

[8] In June 1834, Grey appointed Spring Rice Secretary of State for War and the Colonies, with a seat in the cabinet, a post he retained when Lord Melbourne became Prime Minister in July.

A strong and vocal unionist throughout his life, Spring Rice led the Parliamentary opposition to Daniel O'Connell's 1834 attempt to repeal the Acts of Union 1800.

As Chancellor, Spring Rice had to deal with crop failures, a depression and rebellion in North America, all of which created large deficits and put considerable strain on the government.

That same year he was raised to the peerage as Baron Monteagle of Brandon, in the County of Kerry, a title intended earlier for his ancestor, Sir Stephen Rice.

[3] From 1839, he largely retired from public life, although he occasionally spoke in the House of Lords on matters generally relating to government finance and Ireland.

In a book regarding assisted emigration from Ireland (a process in which a landlord paid for their tenants' passage to the United States or Australia), writer Gerard Moran has suggested that Spring Rice was engaged in the practice.

This union brought much needed money into the family, allowing Spring Rice to maintain his Mount Trenchard estate in Ireland and a London house.