There were no dollars in 1755. In fact, there wasn't even a United States in 1755 (remember what happened on July 4, 1776?).
Please check your coin and post a new question with a more complete description including what pictures are on it and any wording that you can make out.
The Liberty Dollar is worth One Dollar!
how much is a 1 dollar from 1781 worth
Check that coin again. There was no such thing as the United States in 1755, let alone a U.S. one dollar coin.
A US dollar is worth 0.9822561 of a dollar in Europe
It's worth one dollar.
1 Australian dollar is worth 1.06 Dollar in US
A dollar.
A dollar.
One dollar.
What you presumably have is a James Buchanan presidential dollar coin. It was minted in 2010 and is worth one dollar.
It's still worth one dollar.
one dollar worth 30 rublei