The only unknown animals in 1803 in the USA were some desert animals like:
The jumping mouse, the tiaganoose(another type of desert rodent).
lion and tiger
flying pigs and Worms lots and lots of worms
the dadaline and the cocrioch
1803
The Louisiana Purchase in 1803 for $15 million.
April 30, 1803 is the date that the negotiators signed the purchase treaty in Paris. The US Senate ratified it on October 20, 1803 and the US formally took possession on December 20, 1803.
1803 (May 2, 1803)
thre could be 100,000,000,000,000,000,000,00,000,000 unknown animals
cow
Lewis and Clark finally reached Louisiana in 1803.
Louisiana
In 1803.