Mary Ann Thomas brought a case against Eliza Lawson and others, the heirs at law of James Lawson. Mary Ann Thomas claimed that she was entitled to certain property from James' estate due to an agreement between her and him prior to his death. The court found in favor of Eliza Lawson and the other heirs, ruling that there was no evidence presented by Mary Ann Thomas proving her claim or showing any legal right on her part with regards to the property. Ultimately, it was determined that Mary Ann had not established sufficient proof for her claims regarding ownership of the disputed property belonging to James’ estate.

In the case of Mary Ann Thomas v. Eliza Lawson and others, heirs at law of James Lawson, deceased, by George A. Gallagher their guardian ad litem, the Supreme Court was asked to decide whether a deed from James Lawson to Mary Ann Thomas was valid or not. The majority opinion held that it was invalid because there were certain formalities required for such deeds which had not been followed in this instance; however Justice McLean dissented with his own opinion on the matter. He argued that although some formality may have been lacking in this particular deed due to its age and circumstances surrounding its execution, it should still be considered valid as long as all parties involved agreed upon its terms and conditions when it was made - which they did in this case - since no fraud or mistake could be proven otherwise. Furthermore he noted that if any party felt aggrieved by the transaction then they would have taken action against it sooner than now after so much time had passed without objection being raised before then.