John Williamson started the New Zealander as a weekly newspaper in 1845 and it was the main competitor of the Southern Cross. These were the only two newspapers that became established in Auckland for any significant period of time before the 1860s.

The New Zealander began during the depression following the war against Hone Heke in Northland. The paper aimed to represent the interests of the average settler and Māori. It was the view of the New Zealander that the interests of the larger land claimant groups were already receiving more than enough coverage in the Auckland Times. Ironically the Times closed shortly after the New Zealander began publishing in June 1845.

The Southern Cross was temporarily suspended in 1845 leaving the New Zealander to continue without competition until the Southern Cross was revived in 1847. The New Zealander responded to this by publishing bi-weekly. In 1848 Williamson took William Chisholm Wilson into partnership.

The paper steadily increased its influence. By 1859 it was the leading paper in New Zealand and in 1863 it became a daily. Also in that year the partnership split over the war against the Māori. Williamson was against it while Wilson was for it. Wilson left to set up the New Zealand Herald and Williamson carried on as the sole owner.

The New Zealander incurred some criticism for its comments on the war. In June 1864 fifty men from the HMS Esk threatened to pull down the newspaper office after one of the paper's correspondents suggested that Captain Hamilton's death at Gate Pa was due to his men having deserted. Williamson refused to apologise but did offer to print a rebuttal from the seamen in his paper.

By this time the New Zealander had begun to lose influence and support. The paper's pro-Māori policy was moderated but it was too late. In 1865 it couldn't sustain daily publication and had to revert to bi-weekly. In May 1866 the office burnt down and the paper stopped.

The New Zealander and the Southern Cross are good examples of the way the country's press was politically aligned at the time and this was mirrored in other centres around New Zealand.