Scientists learned much of what we know about previous cultures through archeology. Prepare a unit in which students will become archeologists studying an ancient culture such as the Mayans or the Egyptians. Discuss how archeologists gather data and extrapolate from artifacts. Make "artifacts" using small objects in the classroom and burying them in a shoebox of dirt. Ask students to make sketches of their findings, record their findings in chart form and write a paragraph explaining the significance of the artifacts, just as real archeologists would do.
A project that can be adapted to many different units of study is a newspaper. Design a long-term project in which the students must report the events leading up to the Civil War or the Revolutionary War. Discuss bias in journalism and propaganda before the assignment. Have students write "filler" material from the time period as well, such as want ads and obituaries in addition to news stories. For a short project, assign each student a country and have them write one article about a current event specific to that country.
To help students appreciate each others' cultures, hold a cultural fair in your fifth grade class. Allow each student to choose an aspect of their culture or heritage to research. This might be something such as Scandinavian cooking, Mexican blanket weaving or Brazilian dance. Ask students to conduct an interview as well as collect data from books and Internet sources. Have each student present their project on tri-fold poster board and bring in examples or photos of their topic.
A project that fifth graders can complete to reinforce social studies concepts and hone their language arts skills is to keep a diary. For any time period that you study, talk about what people's lives were like in that society and era; this will give students background to use as they write a journal. Either allow students to invent a character, or assign them to write from a different character's perspective for each entry. For instance, in a unit about the Oregon Trail, have the students write an entry for each member of a family traveling west.