The new HaT 75mm cannon is the famous "French 75." US Army troops used these in great numbers all during the Great War. After the war, US Army horse cavalry units continued to use these unchanged from the First World War appearance until about 1942.
Other US Army units used them at least until 1939. I have photos of them in use with the Georgia National Guard. The gun shield has been removed and the wooded spoked wheels have been replaced with a dished steel wheel with a rubber rim for towing by motor vehicle. They use a small two axle hard cab truck to tow them.