sentences:  Ottawa and LaSalle County had a large Irish population due to the importance of Ottawa as a trade and industrial center on the canal.The election of the LaSalle County sheriff hinged on the Irish vote when a New Englander Woodruff was replaced as sheriff by William Reddick a successful Irish landowner following Woodruff's role in putting down a riot along the canal in 1837.Irish and German immigration to LaSalle County, especially LaSalle.