Complex sentence: In the town he also set up a mercantile store and bank down the road from the Murphy & Dolan mercantile and banking operation established a few years earlier by James Dolan, Lawrence Murphy and John H. Riley, who were all of Irish ancestry.
Split into simpler sentences: In the town he also set up a mercantile store and bank down the road from the Murphy & Dolan mercantile and banking operation. It had been established a few years earlier by James Dolan, Lawrence Murphy and John H. Riley, all of Irish ancestry.