If the president has vetoed a bill passed by congress, what can congress do about it?

The Congress can override a veto by passing the act by a two-thirds vote in both the House of Representatives  and the Senate.

According to the Constitution. All legislation passed by both houses of Congress must be presented to the President. ... If the Congress overrides the veto by a two-thirds vote in each house, it becomes law without the President's signature.

i'm not certain but i'm pretty sure it was spanish and portuguese america.

europeans carried a hidden enemy to the indians: new diseases. native peoples of america had no immunity to the diseases that european explorers and colonists brought with them. diseases such as smallpox, influenza, measles, and even chicken pox proved deadly to american indians