The TeachersCorner.net offers daily writing prompts. They include a PDF of the writing prompts with an image and the prompt so that a teacher using a projector can easily display the prompt for their students. For example, the prompts for March 9th is:
“On this day in 1454, explorer Amerigo Vespucci was born. The continent we live on is named after Vespucci. What part of the world would you like to sail to and explore? Why did you choose this destination? PDF“
They also provide a nice list of Monthly Units, Activities, and Resources. There is a set of Google ads at the top of the content that you will need to scroll past.