Thank you to all here who have taken the time to explain why they find this ATL implausible. Let me come back at you again.
The 1497 English expedition led by Italian Venetian
John Cabot (Giovanni Caboto) was the first of a series of French and English missions exploring North America.
In 1520–1521 the Portuguese
João Álvares Fagundes, accompanied by couples of mainland Portugal and the Azores, explored Newfoundland and
Nova Scotia.
In 1524, Italian
Giovanni da Verrazzano sailed at the behest of
Francis I of France, who was motivated by indignation over the division of the world between Portuguese and Spanish. Verrazzano explored the Atlantic Coast of North America, from
South Carolina to
Newfoundland, and was the first recorded European to visit what would later become the
Virginia Colony and the United States. In the same year
Estevão Gomes, a Portuguese
cartographer who'd sailed in Ferdinand Magellan's fleet, explored
Nova Scotia, sailing South through
Maine, where he entered
New York Harbor, the
Hudson River and eventually reached
Florida in August 1525.
From 1534 to 1536, French explorer
Jacques Cartier, believed to have accompanied Verrazzano to Nova Scotia and Brazil, was the first European to travel inland in North America, describing the
Gulf of Saint Lawrence, which he
named "The Country of Canadas", after
Iroquois names, claiming what is now Canada for Francis I of France.
Is it really so implausible that any of these OTL voyages couldn't have taken place prior to 1519, and couldn't have gone to Mexico before the Spanish did?