Conversation so far:
Where did Matthew Fontaine Maury grow up?
He was born in 1806 in Spotsylvania County, Virginia, near Fredericksburg.
Did they stay there?
The family moved to Franklin, Tennessee, when he was five.
How or when did he become interested in astronomy or the ocean?
He wanted to emulate the naval career of his older brother, Flag Lieutenant John Minor Maury.
What made him interested in astronomy?
Maury began to study the seas and to record methods of navigation.
What were some methods of navigation that he used?
One of the experiences that piqued this interest was a circumnavigation of the globe on the USS Vincennes.
How did he start his career?
he obtained a naval appointment through the influence of Tennessee Representative Sam Houston, a family friend.

Question: When was he appointed?
Self-contained rewrite: When was Matthew Fontaine Maury appointed?