<Tr> <Th> No . </Th> <Th> Amendments </Th> <Th> Enforced since </Th> <Th> Objectives </Th> <Th> Prime Minister </Th> <Th> </Th> </Tr> <Tr> <Td> </Td> <Td> 15, 19, 85, 87, 174, 176, 341, 342, 372 and 376 . Insert articles 31A and 31B . Insert schedule 9 . </Td> <Td> 10th May 1951 </Td> <Td> Added special provision for the advancement of any socially and educationally backward classes or for the Scheduled Castes and the Scheduled Tribes . To fully secure the constitutional validity of zamindari abolition laws and to place reasonable restriction on freedom of speech . A new constitutional device, called Schedule 9 introduced to protect laws that are contrary to the Constitutionally guaranteed fundamental rights . These laws encroach upon property rights, freedom of speech and equality before law . </Td> <Td> Jawaharlal Nehru </Td> <Td> Rajendra Prasad </Td> </Tr> <Tr> <Td> </Td> <Td> Amend article 81 (1) (b). </Td> <Td> 1 May 1953 </Td> <Td> Removed the upper population limit for a parliamentary constituency by amending Article 81 (1) (b). </Td> </Tr> <Tr> <Td> </Td> <Td> Amend schedule 7 . </Td> <Td> 22 February 1955 </Td> <Td> Re-enacted entry 33 of the Concurrent List in the Seventh Schedule with relation to include trade and commerce in, and the production, supply and distribution of 4 classes of essential commodities, viz., foodstuffs, including edible oil seeds and oils; cattle fodder, including oilcakes and other concentrates; raw cotton whether ginned or unginned, and cotton seeds; and raw jute . </Td> </Tr>

List of important amendments of the indian constitution