Is there a website which shows all the different reverse designs which have appeared on the Lincoln cent? I'd like to get my second graders--and their parents--involved in a scavenger hunt for as many different varieties they can find.
You can always Google - Penny United States Coin https://en.wikipedia.org/wiki/Penny_(United_States_coin)
Us mint has education tools for teachers, kids area of the website. may see if there is anything useful. coin dictionary ect.
There are a couple of websites on this. E.g. http://lincolnpennies.net/ https://www.thesprucecrafts.com/2009-lincoln-pennies-4071198
This thread feels so familiar... https://www.cointalk.com/threads/need-help-with-class-penny-search.334891/
The original idea probably came from one of those teacher sharing sites... best practices, how to get your student's family engaged with learning - those kinds of things. Teachers have been notorious for sharing ideas, since, well, Socrates found his log.
There have been seven major reverse designs for the Lincoln Cent. Here they are: 1909 - 1958, The Wheat Ears Reverse. 1959 - 2008 The Lincoln Memorial Reverse In 2009, the Mint celebrated the 200th anniversary of Lincoln's birth with four reverses that celebrated his life. Birth and Early Childhood The Formative Years Professional Life Presidency In 2010 the Mint introduced the current Shield design. All of these cents are Proofs, which are special coins that are struck for collectors. The coins you will find in circulation are not as sharp as these coins. The first one is a 1909 Matte Proof, which the mint produced 1909 until 1916.
Johnmilton has shown the seven major types, there are also several small changes from changes in the hub used on the Lincoln Memorial design but that would probably be beyond the scope of what you are wanting to do.