Hi Susan,
I am also researching the Mckenna-Donnelly family who settled in Muskego, Wisconsin and have hit the proverbial brick wall. I am wondering if there is perhaps an old family bible or letters out there somewhere that might have some clues. I have been unable to find any immigration or naturalization records, and unfortunately the early census records did not record that information.
I have also come across a few discrepancies regarding Simon McKenna's immigration. The biographical portrait you speak of states that Simon arrived in 1834 from County Meath. I found that unusual, as it appears that the McKenna surname is mainly found in County Monaghan. To make matters more confusing, my sister told me she once saw a family bible that said Margaret McKenna (Simon & Mary's daughter) was from County Cork, which obviously isn't true as she was born in Wisconsin. I also came across a genealogy post from a Kevin McKenna who said Simon arrived in 1835 from County Meath. I replied to his post, but did not receive an answer. I also have an immigration year of 1837 in my notes, but unfortunately I do not recall the source.
The biographical portrait also states that Simon came to Wisconsin in 1839 and bought 40 acres, then went back to NY to collect his family, returning to Wisconsin in May of 1840. However, I have the 1840 Census for Ward 13, New York, NY for the houshold of a Simon McKinney, which was taken June 1st, 1840. I have deduced that this is most likely the same Simon, as it shows 1 male under 5 (probably James, age 1), 1 male between 30-40 (probably Simon, age 38), 1 female between 20-30 (probably Mary, age 25). I also have the land transaction document, which took place in 1843, not 1839, which I have attached.
Castle Garden has not been much help in finding Simon, although I did find a possible entry for Mary Donnelly, age 20, servant, arriving 27 May 1834 on the ship HERALD from the port of Liverpool, destination New York. Last residence appears to be County Cavan, Ireland--a couple counties south of Tyrone.
The biography states that Simon was the treasurer and supervisor of the town of Waukesha, so I guess it wouldn't hurt to look at the township records if they exist. The Muskego Historical Society is another possibility, but I doubt these sources will have the type of information we are looking for. Did you find anything on your trip to Ireland?
Joanne