Who invented cough drops?

Here is an educated guess-

Fisherman's Friend® cough drops began with a liquid form first made by pharmacist James Lofthouse in 1865 for fisherman working the Icelandic waters. The solid candy form was created much later by Lofthouse of Fleetwood, Lancashire, England and is now available in many different flavors in over 100 countries.

http://www.wisegeek.com/what-is-a-cough-drop.htm

Here's another guess:

Early History -- The concept of alleviating a cough with herbs and extracts is nothing new. For millennia, people have used natural substances---such as goat's milk---to remedy coughs and sore throats, and the Roman physician Galen first used cough suppressants to treat patients in the second century. Because sugar was a rare and expensive commodity throughout much of history, cough remedies didn't take the form of candy until the 19th century, when sugar had become widely available and sugar-based lozenges were cheap enough for mass production.

First Cough Drops -- Although no single person holds the title of "cough drop inventor," William and Andrew Smith---known as the Smith Brothers---pioneered the cough drop industry in the mid-19th century, producing and packaging the first widespread cough drop brand. After the Smith Brothers' father learned of a special cough candy formula, the family began producing homemade cough drops and selling them locally in New York's Hudson Valley. The cough drops quickly gathered a base of consumers, and in 1852, the Smiths began advertising their cough candy in the local newspaper, leading to burgeoning popularity of the product. After their father passed away, the Smith Brothers inherited the business, and they launched the first factory-produced line of cough drops in 1872.

https://en.wikipedia.org/wiki/Smith_Brothers

The first cough drop, Halls(r) Mentho-Lyptus, was invented by the British company, Halls Brothers. They were in the US by the 50s.

https://www.jhunewsletter.com/article/2018/03/the-sweet-origins-of-modern-cough-drops

It was definitely NOT Halls, despite the claim at the link posted by speeddemon_1. They were first made in the 1930s, but a company founded in 1889, so both Fisherman's Friend and the Smith Brothers definitely predate them.

https://en.wikipedia.org/wiki/Halls_%28cough_drop%29