Tooting the horn, singing, and even dancing, the Obamas used a weekend train journey re-enacting Abraham Lincoln's journey to his 1861 inauguration to celebrate a special family occasion – the new First Lady's 45th birthday.
As they travelled from the eastern city of Philadelphia down to Washington DC, Malia and Sasha had a surprise in store for their mum.
When the first couple got off to address a rally the girls got to work turning one carriage into a party venue, complete with crepe paper and banners, earning a delighted whoop of surprise from the birthday girl. Later the revellers, including Michelle, could be seen boogying on down through the windows.
The girls' father Barack Obama also did his bit, telling supporters at the first stop in Wilmington, Delaware, about the significance of the day. At which the crowd erupted in an enthusiastic rendition of Happy Birthday.