After many long years, the Illinois Michigan Canal had its official start on July 4, 1836.    The official ground breaking ceremony took place at the Chicago River.  The steam boat Chicago transported dignitaries and pleasure seakers from Lake Michigan to the site of the ceremony.  The Declaration of Independence was read.  Speeches were given by dignitaries.   Toasts were made.  The ceremonial turning of the sod was done.  Absent from this official ceremony were any of the laborers who would perform any of the work on the canal.   After the completion of the festivities, the Chicago  steamed back to Lake Michigan and was pelted with rocks by a group of Irish workers stationed in a quarry on the bank of the Chicago River.   12 of these workers were ultimately arrested.   A definite clear motivation for the attack was never made clear.   Perhaps it was due in part to their lack of inclusion in the celebration.