Ada County was named after Ada Riggs but there's debate on whether or not she was really born in Idaho.


Ada Riggs is the daughter of H.C. Riggs who was the Boise legislature that introduced the bill that established Boise as the capitol of Idaho back in 1864.


My history is not the best so if I get some of this wrong, please correct me.  There's a lot of reports saying Ada was the first white child born in Idaho but that isn't true.  She was born in California.  Even Wikipedia has it wrong...

Ada County was created by the Idaho Territorial Legislature on December 22, 1864, partitioned from Boise County. It is named for Ada Riggs, the first pioneer child born in the area and the daughter of H.C. Riggs, a co-founder of Boise.[4]Canyon County, which originally included Payette County and most of Gem County, was partitioned from western Ada County in 1891.


If you check out her family tree on they have it right. They say she was born to Henry Chiles Riggs and Mary Ann Lipscomb on April, 3, 1856 in Napa County, California.  So, in fact, the largest county in the state of Idaho is named after a Californian.