American smokehouse padlocks are very common, but are important antique padlocks in the history of American manufacturing. Numerous American manufacturers produced this locks such as Mallory Wheeler, Russel & Erwin, Davenport Mallory & Co., Sargent & Co., William Wilcox & Co. Just to name a few.
During the mid-19th century American manufacturing had a large boom and hardware manufacturers produced a variety of goods and the smokehouse padlock was a common American fixture at the time. The smokehouse padlock styling consists of two steel plates with a simple barrel or flat key. The inner workings of the padlock consists of wards to thwart picking and two or three levers that lock the shackle. The shackle is typically round bar stock flattened and notched on one side to engage the levers and a hole drilled on the opposite side to hinge open or close.

Mallory Wheeler & Co.
A large manufacturer of smokehouse padlocks in the 19th century was a company called Mallory Wheeler & Co. The company was started in 1834 in New Haven Connecticut and was also called Mallory & Co. of Davenport. Mallory Wheeler went out of business in 1913. Here are some catalog pages from the 1874 Sargent & Co hardware catalog showing some Mallory Wheeler smokehouse padlock they sold during that time:
Here’s an example of No. 1014 in the condition found over 100 years after it was manufactured:
The attention to detail was amazing back in 1874, even the back had ornamentation: