A recent change to Canada's citizenship requirements could make millions of Americans eligible for dual Canadian citizenship. Zack Loud of Minnesota was surprised to learn he and his siblings are already considered citizens due to their Canadian grandmother. Immigration lawyers in the US and Canada have seen a surge in applications since the new law took effect on December 15. The new law opens citizenship to those born before the date who can prove they have a Canadian ancestor, like a grandparent. Those born on or after December 15 must show their Canadian parent lived in Canada for 1,095 days. Nicholas Berning, an immigration attorney, says his practice is overwhelmed with cases. Attorney Amandeep Hayer has seen consultations increase dramatically. Canada has been updating its citizenship laws for decades. Previously, Canadian citizenship by descent was limited to one generation.