(SMACK!) Next time give us a photo of the TOP, since that is where the markings are!
US Revolver was a secondary brand of the Iver Johnson Company. They were distinguished by the markings, unfluted cylinder, and did not use the transfer bar firing system. They were made from 1911 to 1933. Since about 10,000 were made each year for the first 10 years, yours is likely a first year gun. They originally sold for about $6.00 (which was a fair bit of money in 1911) originally in .22 rimfire, 32 S&W and .38 S&W. .32 S&W Long was added in later years, they were in blued or nickel plated, with hard rubber grips. There is also a hammerless version, top break. Yours is the solid frame model.
PS- .38 S&W is NOT .38 Special!