Nehru joined the Indian National Congress because he was deeply influenced by Mahatma Gandhi. It was Gandhi's insistence on action to bring about change and greater autonomy from the British that sparked Nehru's interest the most.
The British didn't give in easily to Indian demands for freedom, and in late 1921, the Congress Party's central leaders and workers were banned from operating in some provinces.
Nehru went to prison for the first time as the ban took effect; over the next 24 years he was to serve a total of nine sentences, adding up to more than nine years in jail.
While in prison Nehru studied Marxism. From then on the backdrop of Nehru's economic thinking was Marxist, adjusted as necessary to Indian conditions.