Young girl starts letter writing campaign for troops

>> it through day

>> reporter: so savannah wrote a song for her best friend .

>> i thought about what these soldiers were doing. i said wilson, we need to do more than this. is there anything we can do? we came up with savannah 's soldiers.

>> reporter: savannah started a letter-writing campaign for soldiers being deployed with wilson's dad.

>> i thought how are we going send 700 letters to afghanistan? she would get kids over and they would start writing letters and sit around the table. it would be maybe 30, 40 letters that they would come up with in a week maybe. and i thought we've got a long way to go.

>> reporter: but savannah was determined and started speak at schools, even going to miami marlins games to get more kids to write letters.

>> they say all kinds of cute things. the little kids, they write the cutest letters because they don't know how -- they're not the best spellers. instead of country, they'll write crountry.

>> reporter: savannah and her family will mail them to battalions stationed half a world away .

>> when you get a letter from a little kid that is telling you good job and we're thinking of you, thank you, you can't explain it.

>> it helps with the morale. it helps get through the day, through the tough situations that they're dealing with in afghanistan.

>> reporter: some soldiers take photos with savannah 's letters and show their gratitude on her facebook page.

>> they're always smiling. they're holding up letters with a smile on their face. it's really amazing to see that we're doing a great thing. it's working.

>> reporter: now savannah hopes kids and schools in all 50 states will join her letter-writing campaign.

>> she dawes really good job of speaking and communicating with the kids. extremely proud of her.

>> she's just passionate about it and she loves what she's doing.

>> reporter: for the soldiers, the letters are a touching tribute, from a little girl with a big heart.

>> savannah madison is my hero. she's made a difference in my life. and i appreciate her.

>> you have really, really blessed me. you've blessed the soldiers that are still over there. you're awesome. thank you very much. i really do appreciate it.

>> reporter: for "today," kerry sanders , nbc news, miami.