Explanation:

The 1929 Session of Indian National Congress is of significance in the history of the Freedom Movement because the attainment of Poorna Swaraj was adopted as the goal of the Congress.
The Indian National Congress, on 19 December 1929, passed the historic ‘Purna Swaraj’ – (total independence) resolution – at its Lahore session. A public declaration was made on 26 January 1930 – a day which the Congress Party urged Indians to celebrate as ‘Independence Day’. The declaration was passed due to the breakdown of negotiations between leaders of freedom movement and the British over the question of dominion status for India.
Do you know?
The Purna Swaraj resolution was seen as a critical symbolic event by leaders of the freedom movement and Indians in general. During the constitution-making process during 1946 -1950, members of the Assembly decided to choose 26 January 1950 as the date for the Constitution of India to come into effect; this was done to honour the date of the public declaration of Purna Swaraj.