Complex sentence: During the period 1803-5 he lived in Pennsylvania and returned to Cobacec in 1805 and moved to York (now the City of Toronto) Upper Canada that same year.
Split into simpler sentences: During the period 1803-5 he lived in Pennsylvania and then returned to Cobacec. He then migrated to 1805 and moved to York (now the City of Toronto) Upper Canada that same year.