What are those taxes on my airline ticket ?

Today i bought an airline ticket using a coupon I had received when I was voluntarily bumped from a flight. Even though I had more than enough to cover the cost of the base fare, I was still charged for taxes and fees. It was just under $75. So, I thought, what are these fees for?

( The website indicates it was as of 2017 ... Airport Taxes and Fees Update )

Here goes :

U.S. Transportation Tax - 7.5% beginning 10/l/99 until further notice

U.S. 09/11 Security Fee - Up to $5.00 - charged per one-way trip to fund screeners, equipment, and other costs of the Transportation Security Administration

U.S. Flight Segment Tax - $3.00 - Domestic passenger tax that applies to journeys that begin and end in the U.S. or the 225 mile buffer that extends into Canada or Mexico.

U.S. Passenger Facility Charge - Up to $4.50 -charged by an airport for airport improvements. Up to four PSCs can apply to each ticketed journey and a maximum of two PFCs per each one-way trip.