Porto Alegre is a city in the south of Brazil where Raquel lived for several years. It is a long way away and getting there from Seattle generally takes about 24 total hours of travel time, including two connections. Porto Alegre's airport code is POA.
In general, international airfare is much cheaper if you buy it earlier. Getting the best deal on airfare can require some work- sometimes travel agencies have the best deals, and sometimes it is cheaper to buy your trip in pieces than to buy it all at once. Connecting flights from Seattle and other cities go through San Francisco, Dallas, Houston, Chicago, New York, Miami, Atlanta, and Orlando. The connections to Porto Alegre in South America are generally in São Paulo (Guarulhos), though there are flights that go through Rio de Janeiro and Lima, Peru.
I generally buy airfare from Seattle to São Paulo and then buy the ticket to Porto Alegre separately.
Some websites to search for international airfare:
For travel within Brazil (US and international credit cards accepted):
For travel within Brazil - payment more complicated:
