This is the only photo of Thomas C. Carroll that I'm aware of at this time.  I've always loved this photograph because Thomas seems to have such a twinkle in his eyes.  Unfortunately I have not come across a photo of Margaret, but I plan to keep looking. 

Thomas was born in County Tipperary, Ireland on 7 Jul 1831 according to the information on his tombstone.  Carroll, even Thomas Carroll, was a common name in County Tipperary.  His death certificate lists his father's name as Thomas Carroll but the mother's name was unknown.  It hasn't been too difficult to follow Thomas once he was in the USA even though it's impossible to determine what ship and when he arrived.  There were many Thomas Carrolls that left Ireland during the Potato Famine years of 1845-1852. 

The voyage to America must have been most unpleasant.  Travelers had to furnish their own food.  The Captain of the ship furnished the water.  Any bad weather or damage that needed repair could extend the usual 8-10 week voyage causing passengers to run out of food.  The crew of some ships grossly mistreated  their passengers. Many did not survive the crossing, especially the children and elderly. Since it was primarily the poor who were traveling they often arrived without a penny in their pocket.  If they were unable to work they were taken directly to the poor house.  Others without money to travel from the city where they arrived usually lived in crowded tenements.      If you had a little money and could leave the city, you had a chance of finding better paying work and buying a little land of your own.

Thomas must have brought a little money with him.  Although it's unknown exactly when and where he arrived, he ended up in Fairfax Station, Fairfax, Virginia and was one of the many Irishmen recruited to build the Orange and Alexandria Railroad.