He served two partial terms in the Legislative Assembly, the lower house of the Parliament of the Province of Canada, as a member of the French-Canadian Group under the leadership of Louis-Hippolyte LaFontaine.

The suburb of Outremont was developed on his properties, and Notre Dame des Neiges Cemetery is on land he previously owned.

He donated four of the lots he owned in Côte-Saint-Louis to Bishop Ignace Bourget, who used the property to establish the Montreal Institute for the Deaf and Mute in 1879.

Along with Louis-Hippolyte LaFontaine and Joseph Bourret, Beaubien was co-owner of the sub-fief of La Gauchetière, which they had acquired from the Sulpician order in 1844.

The first was the Banque du Peuple, created in 1835 by a partnership headed by Jacob De Witt and Louis-Michel Viger.

[1][2] Beaubien also served two partial terms in the Legislative Assembly, the lower house of the Parliament of the Province of Canada.

He was in time to participate in a major vote in the Assembly, condemning the Governor General, Sir Charles Metcalfe, for not following the principles of responsible government.

He again was a member of the French-Canadian group, and again participated in a major vote, in favour of the Rebellion Losses Bill, introduced by the LaFontaine-Baldwin ministry.

Its purpose was to compensate individuals in Lower Canada who had suffered property losses in the Rebellion, but attracted intense opposition from the English-aligned Tories.

When the bill passed and Governor General Lord Elgin gave royal assent, Tories in Montreal rioted and burnt the Parliament buildings.

One son, Louis Beaubien, also went into politics, sitting at various times in the Legislative Assembly of Quebec and the House of Commons of Canada.