It all started out with the 3 pounder cannon in particular which George Washington and the American Colonials used to fight for their independence against the British Empire in the late 1700s. It had an effective range of a few hundred yards and could be fired about once or twice a minute by a well trained crew. 


Eat lead Red Coat Nazis.

Then came the 6 pounder cannon around the time of the American-Mexican War in the mid 1800s. It had a little longer range than the previous 3 pounder cannon and it fired "grapeshot" which is basically like a scaled up version of buckshot used in modern day shotguns firing lots of golf ball sized projectiles at once. It worked great for taking out large sections of Mexican infantry.


Take that illegal aliens.

In the American Civil War between 1861 and 1865 the most popular cannon was the 12 pounder Napoleon Cannon. It had rifled barreling which meant it could be fired much further and much more accurately. The Northern forces mainly had them while the Southern forces used inferior cannons and it's one of the main reasons why they lost the war for their independence.


Damn yankees.

In WWII came the M101 Howitizer with a range of about 7 miles. It was used by the U.S. military all the way up through the Vietnam War and is still used by dozens of countries still to this day.



Currently we're primarily using the M198 and the much lighter M777 Howitzer. A crew of 5-10 men can fire it about 4 times a minute and can reach out and touch someone at about 15-20 milies with the kill radius of the high explosive shell upon impact being about 50+ yards.



The latest bad boy in the Pentagon's pipeline is the XM1203.

 

The loading, aiming and firing mechanisms are all automated so it only requires a crew of 2 operators to field. And best of all it can fire the latest GPS guided high exlosive Excalibur artillery round which can be fired in almost any direction and land within 5 yards of the target at up to 25 miles - severely increasing the killing power of U.S. artillery while also greatly limiting civilian casualties. And better yet it can fire 10 rounds a minute in various arcs which means 5+ shells can all land on the target at the same exact time from one gun. It can even link up with unmanned UAVs like the Predator drone and orbital satelites and fire on targets that are out of its line of sight like on the other side of mountain ranges miles away with pinpoint accuracy.

http://www.youtube.com/watch?v=2ePfl4WpIzg 
http://www.youtube.com/watch?v=MYMK1diiW3I 

That's quite a leap in technology from front loaded 12 pounder cannons to GPS guided automated mobile Howitzer's in roughly 100 years. Gives me wood.

The trajectory linked shots is pretty bad ass. Instead of hitting the same location with multiple shots I could see that being used to hit a large blanket area at the same time so people near the initial blast can't prepare for more shells.

I wonder how hard it is for developed nations to shoot down GPS satellites

No idea...