Prior to the establishment of the INTO, in 1868, a number of local teachers assciations had been formed, one of the oldest of which was the Wexford National Teachers Association founded in 1858. Other associations existed in, for example, Strabane, Moate, Mullingar, Limerick, Clones, Cavan, Dingle, Cork, Macroom and Ennis. In June 1868, a Central Teachers Association for national teachers in Dublin was formed and on August 15th a meeting was held, representative of 47 associations, with the objective of consolidating the different teachers' associations, and so the INTO was formed. By the end of 1869 there were 168 local associations affiliated to the INTO and by the end of 1875 there were 235. The main objective of the union as stated in rule book, was "the promotion of education in Ireland, the social and intellectual elevation of the teachers and the cultivation of a fraternal spirit and professional intercourse with kindred organisations in other countries." The main problems were low pay, no security of tenure, the absence of any pension scheme, poor training facilities and the deplorable condition of many schools. The average salaries of male and female principal teachers were £42 and £34 per annum respectively, while those of assistant male and female teachers were £22 and £19 per annum respectively. The INTO, through its famous first president, Vere Foster, made many submissions to the Powis Commission, set up in 1868 to examine the position of primary education. A scheme of paying teachers on the basis of results was modified after widespread opposition by the INTO.
     The issue of security of tenure brought the union into conflict with the Catholic church authorities as the local Catholic clergy acted as managers of the vast majority national schools. While contracts of employment were achieved in 1873, teachers regarded themselves as subject to harsh and arbitrary dismissal. The "Maynooth Resolution" of the Catholic hierarchy in 1894 and subsequent amendments allowed teachers the right to appeal dismissal. But the question of school management continued to cause friction both between the INTO and the hierarchy and within the organisation itself. In the ecclesiastical provinces of Armagh and Tuam, for example, the church authorities actually banned INTO members for a time. The union's executive of 1900 felt obliged to accept the Catholic hierarchy's admonition that the union "takes up and maintains unequivocally a correct and becoming attitude towards the bishops and priests of the church." The interests of Protestant teachers was catered for by the Irish Protestant National Teachers Union which was formed in 1895 under the aegis of the INTO.
     A revised Programme for National Schools was inaugurated in 1900 which, while broadly welcomed by the INTO, did not take into account representations by the union, the need for gradual change in educational reform. Around the same time the stem of payments by results was abolished and replaced by a system of fixed incremental scales. However, there was no increase in the teacher salary grant from the government and obstructive conditions were placed in the path of promotion. The inflationary effects of the 1st World War exacerbated these problems. The consequent commendations of the Killanin Committee were, to a large extent, included in the Education Bill of 1919, which provided for greater local control of schools and radically improved housing and pensions for teachers. In the face of very intimidating circumstances the INTO supported the Bill, however, against the strong opposition of the Catholic hierarchy. The Bill was defeated and this ended the last educational legislation for a 32 county Ireland. The INTO did manage to rescue the salary proposals which represented a major break through both in structure and amount. The union's central executive committee booklet on the settlement remarked that for the first time since 1831, when the national education system was established, it could be stated that the salary of an Irish primary teacher "was fair just and commensurate with the important work which he is called upon to perform."
     The union identified firmly with the aim of the new Free State government in creating an educational system based on "Irish ideals and conditions", although reductions in salary scales by 10% in 1923 left a lasting residue of resentment. The new curriculum aimed at the revival of the Irish language and gaelic culture, but the INTO protested at the lack of any considered, gradual approach as many teachers had little or no Irish. Eóin MacNeill, the Minister for Education in the early years of the Cumann na nGaedheal government, did eventually allow for a transitional period representation from the INTO but a revised programme of the Fianna Fail government in 1934 reverted to the more abrupt policy of 1921-22.
     The INTO had a large influence on the educational policy issued by the Party in 1923. The union affiliated to the ILPTUC in 1918, and its secretary, subsequent historian, T.J. O'Connell, was leader of the Labour Party between 1927 and 1932. He served as a Dáil deputy for county Galway (1922-27) and for South Mayo (1927-32). The union continued to operate as a 32 county organisation after difficulties imposed by the 'Emergency' of 1939-45 saw teachers in grave distress and new salary and pension claims were made in 1945. The refusal of the government to come to terms resulted in national teachers going on strike for over 7 months in 1946. Many younger teachers, including Sean (Jackie) Brosnahan, who later served as a general secretary of the union, played a major role in the dispute. While they had popular support in the country the INTQ was eventually forced to ac defeat. The political power of national teachers, however, was generally admitted be central in the Fianna Fail government losing office in the 1948 general election after 16 years in power. Apart from the issues of pay and conditions that h concerned the INTO, the quality of education and its improvement has been a consistent, theme. In 1941 it published the results of its inquiry into the use of Irish as a teachers medium. Wide ranging changes advocating a child centred system of education were proposed in 1947 in a 'Plan for Education'.
     The official Investment in Education Report of 1966 bore out the contention of INTO about the unsatisfactory condition of many national schools. The union executive complained that "in many instances children are being taught in schools where conditions are substandard, and in some cases uncivilised." Large scale improvements have followed. The 1960s also witnessed the abolition of the Primary Certificate (1967) and more varied teaching approaches in general that culminated the New Curriculum of 1971 which was welcomed by the INTO. The Ryan Tribunal of 1968 finally established a common basic salary scale for national, vocational and secondary teachers.
     1975 saw the first change in management structure since 1831. More democratic changes were made in 1980 after pressure from the union. In the same year the union joined with the ASTI and the TUI in negotiating improved salary structures and allowances. In the 1980s the union has been concerned with issues such as the school entry age, equality between the sexes in employment and in-service education. Co--operation with other teachers unions was reinforced in 1985 with the establishment of 'Teachers United' which co-ordinated a campaign for the payment in full of a 10% award by the public service arbitrator. The INTO registered as a trade union in 1921 [351TJ] and has been affiliated to Congress since 1918 - remaining in affiliation with ITUC after the split in Congress in 1945.