The huge expansion of the Buenos Aires and Pacific Railway in Argentina encouraged workers to form a club, after some years playing cricket in different locations, most of them borrowed by other institutions.

The Managers gave their consent the requirement, allowing members to use a land near to Santos Lugares station, in Tres de Febrero Partido.

The same year of its foundation, the club started its participation in the cricket championship for the 1908–09 season, being registered in the second division.

The first title for the club came in 1909, obtaining the Railway Football League, a tournament played amongst railroad related teams.

Hockey continued developing in Argentina, increasing the number of teams taking part of the league.

The women's team also won titles for the club, obtaining the 1932, 1935 and 1936 championship, being nicknamed "Las Imbatibles" ("The Unbeaten").

At the end of the 1930s, Pacific had more than 600 members, forcing the club to put a limit, restricting new memberships to avoid exceeding its capacity.

In 1943, Pacific rugby team promoted to Primera División, after beating Sportivo Francés (now Asociación Deportiva Francesa) in the final match.

After spending some seasons at second division, in 1962 San Martín rugby team won a new championship promoting to primera, after an 8–8 draw with Alumni in the last fixture.

The club disputed a playoff to return to primera in 1983, but lost the decisive match at the hands of Champagnat.

Green represented the Argentine Pampas; blue symbolized the Pacific Ocean (which railway connected to the Atlantic crossing Buenos Aires and the Provinces of Cuyo Region.