I don't know if you are still looking for information on the Tripps or not, but my research indicates this:
Thomas Tripp was the son of Jonathan Houston Tripp & Rebecca Snow.His siblings were:Aaron, Annis, William, Eli, Henry, Nathaniel & John.
Rachel Peterson was born abt. 1811 to John Peterson and unknown wife....John is the first Peterson to appear in Johnson County Census records.Her siblings are believed to be William, Christopher, Sarah, & Susannah.
Rachel and Thomas were married Nov. 19, 1829 in Union County, IL.
Interesting note:Rachel's sisters, Sarah & Susannah married brothers of Thomas.Sarah & Nathaniel Tripp, m. Nov. 10, 1839, Union county, and Susannah and John Tripp m. Aug. 9, 1827 also in Union County.
Hope this helps.If you would like more information, please email me @ email@example.com.