In addition to technology, products and manufacturers, certain types of glass colors will also aid in dating. This type of bottle was probably dip-molded and dates after circa 1820.
Is the base indented with an irregular to round pontil scar?
If a vertical seam ends below the lip and the bottle has no horizontal seams, the bottle was most likely hand-blown into a mold.
This type of bottle-making narrows the bottle's age from the early 1800s to the early 1900s.
Before molds were used to create a more uniform bottle, glass bottles were made entirely by hand by a skilled tradesman blowing air into a blob of hot glass attached to the end of a long pipe.
Such bottles may have air bubbles or lean slightly, or the glass may be thicker in some areas than others. This type of bottle has no seam whatsoever, as it is handmade.
Bottles made by a combination of mold and hand-blowing replaced much of the purely hand-blown bottle crafting in the early 19th century.