Canadian Citizenship Act, 1946

[4] The status of "Canadian citizen" was originally created under the Immigration Act, 1910[5] to designate those British subjects who were born, naturalized, or domiciled in Canada.

"Domicile" was defined as having been resident in Canada for three years, excluding any time spent in prisons or mental institutions.

Where the child born outside Canada was not a minor (i.e., was not under 21 years in age) at the time the Act came into force, proof of landed immigrant status was required to confirm Canadian citizenship.

For example, migrants becoming Canadian citizens were not asked to formally prove that they had ceased to hold the nationality of their former country.

Similarly children born in Canada to non-Canadian parents were not under any obligation to renounce a foreign citizenship they had acquired by descent.