Your answer depends on the size and weight of the letter you want to mail. You can use the online calculator, below, from the USPS, to determine the value in stamps required to mail your letter.
Depends on how many pages the letter is; an average letter, say two pages - one stamp.
About one liberty stamp :)
one
How many stamps are needed to send a letter from Texas to Alaska?
700 Stamps
Depends on the weight and size of the letter.
typicaly 2 stamps
To reach the letter in proper place
It depends on the weight of the letter and the postage rate set by the postal service. You would need to check with the postal service in Haiti for specific information on the number of stamps required to mail a letter to Pennsylvania.
if it weighs an ounce or less, three stamps.
How many stamps to STOCKHOLM
one