The 3.5-mile (5.6 km) extension from Victoria to Brixton with stations at Vauxhall and Stockwell was approved in March 1966.
Preparatory work had started at Bessborough Gardens near Vauxhall Bridge Road in May 1967.
The contract was awarded on 4 August 1967.
A proposal to build Pimlico tube station received Government approval on 28 June 1968.
In July, the Prince of Wales and the Duke of Edinburgh visited tunnel workings under Vauxhall Park.

The Brixton extension was bored using the older Greathead shield.
Although slower, use of the tunnelling shield allowed easier digging through the gravel strata south of the Thames.
It was opened by Princess Alexandra on 23 July 1971, who made a journey from Brixton to Vauxhall.
On opening, it was the first new section of Underground to open south of the Thames since the extension of the City and South London Railway from Clapham Common to Morden in 1926.
The final piece of the Victoria line, Pimlico station, opened on 14 September 1972.

London Transport considered extensions to Streatham, Dulwich and Crystal Palace to provide a connection to southeast London and Kent but no construction work was undertaken.
The 3.5-mile (5.6 km) extension from Victoria to Brixton with stations at Vauxhall and Stockwell was approved in March 1966. Preparatory work had started at Bessborough Gardens near Vauxhall Bridge Road in May 1967. The contract was awarded on 4 August 1967. A proposal to build Pimlico tube station received Government approval on 28 June 1968. In July, the Prince of Wales and the Duke of Edinburgh visited tunnel workings under Vauxhall Park.
The Brixton extension was bored using the older Greathead shield. Although slower, use of the tunnelling shield allowed easier digging through the gravel strata south of the Thames. It was opened by Princess Alexandra on 23 July 1971, who made a journey from Brixton to Vauxhall. On opening, it was the first new section of Underground to open south of the Thames since the extension of the City and South London Railway from Clapham Common to Morden in 1926. The final piece of the Victoria line, Pimlico station, opened on 14 September 1972.
London Transport considered extensions to Streatham, Dulwich and Crystal Palace to provide a connection to southeast London and Kent but no construction work was undertaken.
Victoria line