Halifax's Pier 21 designated national museum
"This museum highlights the essential role that immigrants have played in the building of our nation and continue to play in shaping our nation, shaping the Canada that we know and love today," MacKay told the crowd.
"This history and this historic place represent one of the jumping-off points for these new arrivals."
The federal government plans to spend $25 million during the next five years to upgrade the waterfront building and develop new exhibitions and programming for the museum, which opened in 1999.
Between 1928 and 1971, 1.5 million people passed through the gates at Pier 21. During the Second World War, 50,000 war brides and their 22,000 children passed through, along with more than 100,000 refugees.
Pier 21 is also the site of a recently unveiled monument called The Wheel of Conscience, which is a memorial to the hundreds of Jews aboard the MS St. Louis who were turned away from Canada on the eve of the Second World War.
"The Canadian Museum of Immigration at Pier 21 is a place of new experiences, new discovery, much emotion and learning," MacKay said.
"This museum invites all of us to share those stories and to enrich our collective memory."
Pier 21 has been, until now, a well-known national historic site. In 2009 — a decade after the museum opened — Prime Minister Stephen Harper announced that it would become one of only two national museums outside Ottawa. Legislation came into force in November.
There are four national museums in Canada: the National Gallery of Canada, the Canadian Museum of Civilization, the Canadian Museum of Nature and the National Museum of Science and Technology.
A fifth national museum, the Canadian Museum for Human Rights, is under construction in Winnipeg.
MacKay said one in five Canadians can trace a relationship to Pier 21, including Minister of State for Seniors Julian Fantino, who came to Canada through Pier 21 in 1953 with his mother and brother.
"It plays a very key role in preserving and promoting what is the very best of our country — our heritage — and contributes to the sense of identity of all Canadians," said MacKay.
"It enhances public understanding of the experience of immigrants as they arrived here in Canada."
The museum's annual operating budget is projected to be up to $7.7 million.