A bit faded, the striped silk suggests a later 18th century date as does the style. The sleeves are on the longer side, with interesting triangular shaped pinks. We so often see the scalloped version. It is nice to see the other style.
What is unusual about this gown is the extreme chevroning to the center back pieces, which at first suggests a remodel somewhere along the way. Chevroning does take place with a stripe on any gown back, but this is much more than any I have ever seen. It is a deliberate design choice.
Looking at the interior view however suggests it was not a remodel. The lining looks intact and original. The construction is in the later style where the two fabrics are turned into each other then seamed. You can easily see the ridges of the seam. It is a shame this gown is so faded. The inside view shows a much more vibrant silk.
Something you don't see often for sale. This pieced pocket is listed with American provenance, and is late 18th, early 19th century. It is always nice to look at these, since the pieces may often be much earlier fabrics than the date of construction. I think the red fabric looks earlier than any of the others.