In 1837 , during the Lower Canada Rebellion , a mandate of arrest was issued against him .
He sought refuge at Saint - Denis , then crossed the United States border with his friend , Louis - Joseph Papineau .
In 1837 , during the Lower Canada Rebellion , a mandate of arrest was issued against him , and he sought refuge at Saint - Denis , then crossed the United States border with his friend , Louis - Joseph Papineau .