A Liberal, his ministry formally ended Manitoba's non-partisan government, although a de facto two-party system had existed for some years.

Greenway moved to Manitoba in 1879, having acquired a large tract of land in the province's southwestern corner (with financial backing from Cameron).

If Norquay hoped to silence the strongest opposition voice by this tactic, he was unsuccessful: Greenway won the riding by 330 votes to 244.

A personal visit from John A. Macdonald boosted Conservative strength, however, and Norquay's government won roughly 21 seats compared to 14 for the opposition.

When his successor David Howard Harrison proved unable to command a parliamentary majority, Greenway was asked by the Lieutenant Governor to form a new administration in January 1888.

Greenway was extremely fortunate, in this sense, that his term began just as the Canadian Pacific Railway voluntarily ended its provincial monopoly over rail travel, subject to hefty compensation from the federal government.

His controversial reforms of Manitoba's school system provoked a national crisis in the 1890s, and are still regarded as his administration's most notable accomplishment.

When Manitoba was created in 1870, the provincial government established a dual school system to reflect the province's demographic balance.

The resulting controversy (known as the Manitoba Schools Question) dominated Canadian politics in the mid-1890s, and divided both the Conservatives and Liberals on the national level.

In 1895, after the Privy Council refused to decide the matter, Conservative Prime Minister Mackenzie Bowell passed remedial legislation defending Catholic rights.

Shortly thereafter, the federal Liberals under Wilfrid Laurier won a national election, and resolved the Schools Questions with a mild compromise (providing minimal state support for Catholic and French education on a case-by-case basis).

Greenway's efforts to introduce secular education into the province were successful, and the Laurier government's bid for further concessions in later years came to nothing.

No longer able to benefit from protest votes, the Liberals were defeated by the Conservatives under Hugh John Macdonald (son of the former Prime Minister) in late 1899.

Many voters were apprehensive about recent East European immigration into the province, and were offended by even the minor concessions which Greenway had made on the education question; the Conservative Party was able to tap into this xenophobia, and won 22 seats out of 40.

An attempt for an early Senate promotion came to nothing, and he continued to lead the Liberals in a desultory fashion through the election of 1903 (wherein his party won only 9 of 40 seats).

Although his loyalty to the Liberal Party was now unquestioned, he accomplished very little in Ottawa and continued to spend most of his time seeking out a comfortable sinecure.

Some regarded his education reforms as discriminatory toward minority groups; others (including some in the social gospel and secular left) saw him as a champion of the public school system in western Canada.