Yes, an official cover sent to Mauritania in 1919!
This is an official cover from the Departamento de Paquetes Postales. It departed San Jose in June 9th 1919. Its destination: Kaiffa, located in the South of Mauritania (French civil territory from 1904 to 1920 when it was declared a french colony), located in Northeast part of Africa.
Just to have an idea on how rare this destination is, the latest census performed in Mauritania in 2013, threw that Kaiffa had 45.000 inhabitants. So imagine in 1919 -almost 100 years ago- the number of inhabitants was way smaller.
According to this cover’s cancelations, it was on transit for almost 2 months. This because it departed San Jose on June 9th and there was no other cancels until it arrived to Senegal on August 5th! According to my investigation even after 1904, then France recognized its separation from Senegal, all correspondence sent to Mauritania, had to go through Senegal first.
What caught my attention is that this cover doesn’t have a received cancel at Mauritania. what comes to my mind is that when it arrived to Senegal, the post office workers -that knew- the person this letter was sent to, knew in advance he was no longer in Mauritania and forwarded the cover to his new location. This saved the cover some time. The new destination was Fougerolles, Haute Saone, France. A town located near the birders with Germany and Switzerland.
The cover arrived to Paris on August 21st to finally find its final destination on August 22nd in Fougerolles, after almost two months and a half in transit.
Another interesting thing about this cover is that the overprint on first stamp is thicker than the others. It seems like a hint of a double overprint.