Gift-giving between foreign diplomats and the U.S. president and white house staff is a surprisingly common event. The gifts that are 'formally' received are officially documented by the U.S. Department of State's 'Gift Protocol Unit', whose records currently span 2002 to 2016. From the state department's website,
"The Gift Office within the Office of the Chief of Protocol receives all diplomatic gifts on behalf of White House and Department of State officials and maintains records pertaining to diplomatic gifts. This includes all diplomatic gifts received by the President, Vice President, and Secretary of State and their spouses"
Above is my attempt at visualising the data that the Gift Office have recorded over the years. The visualisation is a sort-of Sankey diagram, whose connections represent how generous other countries have been in their visits to the US. The bottom row of the diagram represents the countries -- click on one to see a detailed timeline of that country's gift-liness!