The first game of rugby ever to be played in New Zealand under official rugby rules was on the 14th of May 1870.  The two teams that went head to head were Nelson College and Nelson football club. This first game of rugby started something that was much like a cult following.

Credit for the great game of rugby being introduced into New Zealand must go to the great man Charles John Monro.  He was the son of the well known House of Representatives speaker, Sir David Monro.  Although the rules Monro put foward at Nelson football club weren't adopted straight away, they certainly made an impact and in a couple of short months, the Nelson football club's teams were all playing that new game called rugby.

Monro decided it would be a good thing for rugby if he were to get the name and the rules recognised on a larger scale, so he made a visit to Wellington later in 1870.  This resulted in a game being arranged between Nelson and Wellington.  The match was to be played at Petone in September, and won by Nelson two goals to one (a goal was only worth one point).

In 1971 rugby was an organised sport in Wellington (New Zealand's capital) and it had even spread to Wanganui by early 1972.  The largest populated city of New Zealand, Auckland, adopted rugby in 1873, Hamilton in 1874 and by late 1875 the whole country was addicted.  Rugby was established all over the colony, with a team representing Auckland clubs going on a two-week tour of the South Island.  Matches were played against Dunedin, Christchurch, Nelson and Taranaki (the Auckland team lost all of its games).

Now Rugby Unions started to appear all over the country, with the larger ones in Canterbury and Wellington. Rugby was now being formally organised into various clubs and unions around New Zealand.  There were many other Unions to follow but it wasn't until 1882 that the New Zealand Rugby Football Union (NZRFU) was formed.  Basically their purpose was to administer matches at national level.

Finally, New Zealand was introduced onto the international scene when a New South Wales team toured both the North and the South Islands.  In 1884 the first New Zealand team to travel overseas to play rugby toured New South Wales, they wore a blue jersey and a gold fern (New Zealand's emblem).  They won every game they played on the tour, they were the beginning of a legend.

The first British team to play in New Zealand was sent over in 1888, and the New Zealand team carried out the longest tour ever in 1888-89.  Although there were a few New Zealand teams that had already travelled overseas, the very first official team of the NZRFU was to be sent to Australia to play a 10 game series.

From 1893 onwards, New Zealand has been sending teams to all of the major rugby playing countries, and even to countries where the game is very minor.  On the other side of the coin, the NZRFU has been a kind host to players from all around the globe.

By now, the game of rugby is spreading like wildfire - countries are addicted to rugby mania and many of them want a piece of glory for themselves.  Sir David Monro's son, Charles John Monro, has started something that New Zealand has picked up and ran with. Rugby was now New Zealand's sport.

My apologies for not acknowledging my source of information for the dates and place names.
http://www.kiwirugby.com