This is an original US Civil War Cavalry Sword manufactured by Mansfield & Lamb in 1865. The sword does not come with a scabbard. It has a domed pommel cap.
The manufacturer stamp at top of blade near hilt is present but difficult to read due to wear/age:
MANSFIELD & LAMB
FORESTDALE, R.I.
On opposite side of blade top, also stamped:
US
1865
Stamps on top of cap are:
50V
22
Stamp on handle:
22
Blade is about 34.75" long and 1" wide.
Hilt is about 6.25" long and 5.5" wide.
Please see photos for more details.