Early Waltham pocket watches were produced around 1850.  They were actually marked "Howard, Davis & Dennison - Boston", the watchmaking business of three men, David Davis, Mr. Howard, and Aaron Dennison.
They would later become the American Waltham Watch Company. 
VINTAGE AMERICAN WALTHAM POCKET WATCH DIAL! 1 CENT!!

VINTAGE AMERICAN WALTHAM POCKET WATCH DIAL! 1 CENT!!

Price: $2.31
Antique Waltham 18S Pocket Watch Gold Case Runs

Antique Waltham 18S Pocket Watch Gold Case Runs

Price: $131.37
large vintage OMEGA POCKET WATCH 17 jewel

large vintage OMEGA POCKET WATCH 17 jewel

Price: $99.00
large vintage REGINA POCKET WATCH nice

large vintage REGINA POCKET WATCH nice

Price: $49.50
large AMERICAN WALTHAM POCKET WATCH nice

large AMERICAN WALTHAM POCKET WATCH nice

Price: $49.50
Waltham Vanguard 42mm pocket watch 23 jewels

Waltham Vanguard 42mm pocket watch 23 jewels

Price: $154.50
1894 Waltham size 12 pocket watch 17 jewels

1894 Waltham size 12 pocket watch 17 jewels

Price: $14.52
1884 Waltham size 14 pocket watch

1884 Waltham size 14 pocket watch

Price: $33.10
ANTIQUE WRIST WATCH ELGIN gold filled DECO GREAT BAND

ANTIQUE WRIST WATCH ELGIN gold filled DECO GREAT BAND

Price: $9.95
The business plan was to inexpensively manufacture watches without losing quality, a plan that utilized a new concept at the time in watchmaking: interchangable parts.