US Savings bonds used to be easy to own and worked in your favor. We just cashed in one purchased (for 1/2 the face amount) in the early 1990's - it had finally stopped paying 4% interest and was well over the face amount. You used to be able to purchase them at any bank and give them as gifts.
Now, however, they have made it insanely difficult and you can only purchase one online. I was totally turned off, majorly frustrated and disappointed.
That said, if I were you, I would investigate a Certificate of Deposit at your local bank or credit union. Navy Federal just had a limited time offer for a 15 month certificate at 5%! I'm sure there are similar deals around. You can then, "ladder" them up - when their term is done, you can buy another one -or two - for another short term - thus grow your initial investment - yet still be able to access it, when needed.
I realize "banks" are all over the news right now but do some homework and find something you're comfortable with. They're not all bad!