Colonial elections were held in South Australia from 28 March to 21 April 1870.

His replacement, John Hart, survived 19 days before defeat by Henry Ayers, whose period in office lasted only 21 days until defeat by Henry Strangways, who took the parliament into the early election.

Since the inaugural 1857 election, no parties or solid groupings had been formed, which resulted in frequent changes of the Premier.

If for any reason the incumbent Premier of South Australia lost sufficient support through a successful motion of no confidence at any time on the floor of the house, he would tender his resignation to the Governor of South Australia, which would result in another member deemed to have the support of the House of Assembly being sworn in by the Governor as the next Premier.

Informal groupings began and increased government stability occurred from the 1887 election.