If I wanted to look up ancestors that lived in Finland (Kuusamo area) and moved to the US, which library could I visit to do that?

Here are some useful addresses and sources of information:

Institute of Migration in Finland (Siirtolaisuusinstituutti - Finland)
Address: Linnankatu 61, 20100 Turku, Finland
Phone: 02-2840 440
Fax: 02-2333 460

Regional Centre of Ostrobothnia
Keikulinkuja 1
61100 Peräseinäjoki, Finland
Phone: 06-4181 275
Fax: 06-4181 279

Homepage http://www.migrationinstitute.fi/index_e.php Institute has a service called The Emigrant Register for genealogists and the descendants of Finnish emigrants.

The Genealogical Society of Finland (Suomen Sukututkimusseura)
Address: Liisankatu 16 A
FI-00170 Helsinki
Finland
Telephone +358-9-278 1188
Fax +358-9-278 1199
E-mail samfundet@genealogia.fi
Homepage http://www.genealogia.fi/index.php?lang=en
Kansallisarkisto (Finnish National Archive)
Rauhankatu 17
00170 Helsinki
Puh. (09) 228521
Fax (09) 176302
kansallisarkisto@narc.fi
Homepage (in Finnish only) http://www.arkisto.fi