The names we use for some jobs has changed along with the jobs themselves. The  English language has changed too. While not exhaustive, this list should help make sense of some occupations in the census or other old documents.

A person responsible for maintaining accounts and financial
A skilled or artistic worker or craftsman
A person who worked with iron. Iron was called the "black metal" so the blacksmith was a person who worked with it.
car inspector
A person who inspected railroad cars.
A woman who cleaned house for hire. She would usually be employed by a single household.
A general term that applied to almost any industry but usually indicated the man or woman worked in an office. The nature of the work is not indicated by the job title.
day laborer
A person, usually unskilled, who had no steady job and took work as it came. This was a very common occupation in the early 20th century, and before.
A temporary job requiring the man or woman to read and write
and to travel around their designated area to collect information for the census. In early censuses the enumerator was paid by the name and had to provide their own pen and ink.
Usually, but not always, the man or woman who ran (and maybe owned) the grocery store.
A general job title that could be used to mean a variety of
work. By itself, it tells little of what the man or woman really did. Sometimes this term was combined with another, such as farm laborer.
A general term for several trades and industries.
A skilled workman who build using stone or brick.
A student in the Naval Academy.
A chief clerk of any various courts of law.
1. A person who sews.

2. A medieval household officer, often of high rank, who was in charge of serving the dishes at table and of sometimes seating and tasting.

A person who works with metals. This term is usually used with another word to describe a specific type of worker. See Blacksmith. Other examples include gunsmith, copper smith, tune smith.
A person of rank in a medieval household who dispensed, and weighed out, the spices, etc. Spices, especially salt, were extremely expensive and important to a household.
1. A person employed by a large household to manage the domestic concerns of the household.2. An employee on a ship, airplane, bus or train who manages the provisioning of food and attends to passenger needs.

3. A person appointed to supervise the provision and distribution of food and drink in an institution.

A person who works with a lathe.