Thank you very much for your message to Ireland Reaching Out.
Are you interested in tracing where your O'Flaherty side of the family came from? Let me know if you need any assistance if you do.
Was Patrick Hagarty from Clondalkin in Dublin? Do you know if he was born here? You could check newspaper records for the whitewashing incident, but this could be difficult if you don't have a date or an exact location. Even so, the name might not be mentioned in a report at all. Also, you should consider that this might just be a story or an inaccurate memory.
Do you have any details about Mary's arrival to the US - name of ship, etc.. She would probably have had to give information at the place of arrival, so it would be worth looking into this. Also be sure to investigate the Iowa connection - this could be rich with interesting details and stories.
Best of luck in your reseach!