US marine anthem "The Shores of Tripoli", why that location you ask

Why were the US marines going to Tripoli of all places?

Well the US (and Sweden) were fed up of North Afrians capturing their ships and enslaving the people on them so sailed right across the Atlantic to do something about it.
https://en.wikipedia.org/wiki/First_Barbary_War

North Africans (and Turks) enslaving European folk you ask? Yes.
https://en.wikipedia.org/wiki/Barbary_slave_trade

"Pirate raids for the acquisition of slaves occurred in towns and villages on the African Atlantic seaboard, as well as in Europe. Reports of Barbary raids and kidnappings of those in Italy, Spain, France, Portugal, England, Netherlands, Ireland, Scotland, and as far north as Iceland exist from between the 16th to the 19th centuries. It is estimated that between 1 million and 1.25 million Europeans were captured by pirates and sold as slaves in Tunis, Algiers and Tripoli during this time period. The slave trade in Europeans in other parts of the Mediterranean is not included in this estimation"
"Such raids in the Mediterranean were so frequent and devastating that the coastline between Venice and Malaga[16] suffered widespread depopulation, and settlement there was discouraged. In fact, it was said that "there was no one left to capture any longer."
"Supplies from the Black Sea appear to have been even larger. A compilation of partial statistics and patchy estimates indicates that almost 2 million Russians, Ukrainians, and Poles were seized from 1468 to 1694. Additionally, there were slaves from the Caucasus obtained by a mixture of raiding and trading. 16th- and 17th-century customs statistics suggest that Istanbul's slave import from the Black Sea may have totaled around 2.5 million from 1450 to 1700."

I await the BBC documentary about this with baited breath.