From One magazine, a fine overview of the OCA:

The ancient rites of the church of Byzantium unite these Orthodox Christians. Rooted in the New World for more than a century, these North American churches retain strong bonds with the Old World, are divided into a number of ethnic jurisdictions — Albanian, Arab, Belarussian, Bulgarian, Greek, Romanian, Russian, Rusyn, Serbian and Ukrainian — and typically celebrate the divine mysteries in their respective liturgical languages.
One body has attempted to transcend these cultural differences. Originally a jurisdiction of the Russian Orthodox Church, the Orthodox Church in America was established in 1970 and is led by a primate with the title of archbishop of Washington, metropolitan of all America and Canada.
More: http://www.cnewa.org/default.aspx?ID=3595&pagetypeID=4&sitecode=HQ&pageno=1