How do you write a diary entry from the 1800's?

First, you should conduct some research about life in the 1800s, so that you know what to write about in your entry. Second, think up who you are going to be in the 1800s. Possibly a servant girl, a wealthy businessman, a boy farmer; anyone who fits the 1800s description. Third, think up a problem that conflicts your character (the reason why your character is writing a diary in the first place) and if you were writing an entire diary, the problem would be solved in the last entry, which it could make it into a true story. Or, you could end it with a cliffhanger; possibly it would be found years later or start a completely new diary.