President Michael D Higgins has travelled to the midwestern United States for a week-long trip.
The visit is intended to highlight the cultural, economic and political links between Ireland and the US.
He will meet Chicago Mayor Rahm Emanuel tomorrow and Governor of Illinois Pat Quinn early next week.
Mr Higgins is due to discuss Ireland's economic development with them.
The President also has an extensive range of arts and cultural engagements scheduled.
He will meet some of the immigrant support groups who assist Irish people in Illinois and provide services to the estimated 5,000 undocumented Irish in the region.
On Saturday, he will deliver the commencement address at two graduation ceremonies at the Indiana University, where he graduated with a Masters in Sociology in 1967.
He will also be conferred with an honorary doctorate.