Early Life :
Josie Palmer was born in Potchefstroom in 1903, but grew up in Sophiatown, Johannesburg.

Life as an activist:
She joined the Communist Party of South Africa (CPSA) in the 1920s. In 1921 she moved back to Potchefstroom where she became involved in location politics and was elected as secretary of the women's section of the CPSA. Josie married Edwin Mofutsanyana, a leading member of the Communist Party of South Africa (CPSA) and the African National Congress (ANC). Together they lived in an African area even though she classified herself as Coloured. It was when she moved to the local township that she adopted the surname Mpama.

Josie was a leading figure in Potchefstroom in the 1928 campaign against residential permits. It was her first-hand account as an organiser of the Potchefstroom anti-pass campaign of 1929-30 that has helped historians piece together the reasons why women in this small Transvaal town became so highly politicised.

During the late 1920s and 1930s, Mpama wrote for Umsebenzi, the CPSA's journal, in which she highlighted the plight of Black workers and made the connection between workers' struggles and the general political system in the country. In 1929, she was one of the leaders in the beer riots in Natal.
Mpama was politically active throughout the 1930s and 40s. By the 1940s, she was a member of the CPSA's Johannesburg committee, becoming the first Black woman to play a significant role in the CPSA. In 1944, she started working with the National Anti-Pass Council. 

She consistently directed a portion of the Party’s energies towards a women’s organisation in the national liberation struggle and in the struggle for socialism. At the 1947 International Women's Day meeting in Johannesburg, a resolution was passed to establish a 'non-colour bar women's organisation' and the Transvaal All-Women's Union was formed, with Mpama as its secretary. With other women communists like Florence Matomela and Ray Alexander, Mpama played a crucial role in the formation of the multi-racial Federation of South African Women (FSAW or FEDSAW) on 17 April 1954.

Later, while she was president of the Transvaal branch of FSAW, she was silenced by the government when served with a banning order shortly before the historic Women's March to the Union Buildings on 9 August 1956 was to take place.

Mpama was detained during the State of Emergency declared after the Sharpeville massacre in 1960.