Here are some factors that can affect the value of an 1899 US penny:
* Condition: The condition of the penny is the most important factor in determining its value. Pennies that are in excellent condition, with sharp details and no damage, are worth more than pennies that are worn, damaged, or corroded.
* Rarity: The rarity of the penny also plays a role in its value. Some pennies are more rare than others, and this can increase their value. For example, the 1899 Indian Head penny is a rare coin, and it can be worth hundreds of dollars in good condition.
* Errors: Errors can also increase the value of a penny. For example, pennies that have been struck off-center or that have other errors can be worth more than pennies that are free of errors.
If you have an 1899 US penny, you can check its value by looking it up in a coin catalog or by getting it appraised by a professional numismatist.