| Year | Event |
| 1856 | Responsible Government introduced in New South Wales. The New South Wales Parliament becomes bicameral with an elected Lower House (Legislative Assembly – with 54 Members) and an appointed Upper House (Legislative Council – with no fewer than 21 Members). |
| 1858 | Full manhood suffrage (men only) (prior to this only those men who met a modest property or income qualification could vote).
Secret Ballot for voting introduced. |
| 1859 | Queensland was formally separated from New South Wales. The Legislative Assembly was reduced in size from 80 to 72 by the loss of the Queensland seats. |
| 1874 | Elections required to be held for the Legislative Assembly at least every three years. |
| 1889 | Allowances introduced for Members of Parliament (prior to this Members were not paid). |
| 1893 | Plural voting abolished (prior to this voters who fulfilled the qualifications in more than one district could have multiple votes). |
| 1901 | Federation. The New South Wales Parliament handed legislative control of a number of matters over to the Commonwealth Government. |
| 1902 | Women given the right to vote (April for Commonwealth elections and August for New South Wales elections). |
| 1918 | Women permitted to be elected as Members of the Legislative Assembly.
Proportional representation system introduced for the Legislative Assembly (with multiple representatives from each electorate). |
| 1925 | First woman elected to the New South Wales Legislative Assembly (Millicent Preston-Stanley). |
| 1926 | Return to single Member electorates. |
| 1928 | Preferential voting for the Legislative Assembly introduced (prior to this a number of systems were tried including the “first-past-the-post” system and the contingent vote). |
| 1929 | Compulsory voting introduced. |
| 1932 | Lang Government dismissed by the Governor of New South Wales. |
| 1962 | Indigenous Australians gained the right to vote in all States and in Federal elections (prior to this Indigenous Australians, while not officially prevented from voting in New South Wales, were effectively denied the vote through a range of discriminatory regulations and practices). |
| 1975 | Electorate office provided for Legislative Assembly Members. |
| 1979 | Optional preferential voting for the Legislative Assembly introduced. |
| 1981 | Maximum term of Legislative Assembly increased from 3 to 4 years (an election could be called earlier at the discretion of the governing party). |
| 1991 | Legislative Assembly reduced from 109 to 99 Members. |
| 1995 | Fixed four-year terms introduced for the Legislative Assembly. |
| 1999 | Legislative Assembly reduced to 93 Members. |
| 2007 | Amendments to the Constitution Act 1902 to enable the Speaker, when not presiding, to take part in any debate or discussion and vote on any question in the Legislative Assembly. |