21 Gun Salute: The sum of the numbers in the year 1776 

Correctly folding the American flag 13 times: 
To symbolize the original 13 colonies:

1st fold of our flag is a symbol of life.

2nd fold is a symbol of our belief in eternal life.

3rd fold is made in honor and remembrance of the veterans
departing our ranks who gave a portion of their lives for the 
defense of our country to attain peace throughout the world.

4th fold represents our weaker nature, for as American citizens
trusting in God, it is to Him we turn in times of peace
as well as in time of war for His divine guidance.

5th fold is a tribute to our country, for in the words of Stephen Decaur,
"Our Country, in dealing with other countries, may she
always be right; but it is still our country, right or wrong."

6th fold is for where our hearts lie. It is with our hearts that,
"We pledge allegiance to the flag of the United States Of America,
and to the Republic for which it stands, one Nation under God,
indivisible, with Liberty and Justice for all."

7th fold is a tribute to our Armed Forces, for it is through
the Armed Forces that we protect our country and our flag
against all her enemies, whether they be found within
or without the boundaries of our republic.

8th fold is a tribute to the one who entered into the valley
of the shadow of death, that we might see the light of day.

9th fold is a tribute to womanhood, and Mothers. 
For it has been through their faith, their love, 
loyalty and devotion that the character of the men and 
women who have made this country great has been molded.

10th fold is a tribute to the fathers, for they, too,
have given their sons and daughters for the defense 
of our country since they were first born.

11th fold represents the lower portion of the seal of King
David and King Solomon and glorifies in the 
Hebrews' eyes, the God of Abraham, Isaac and Jacob.

12th fold represents an emblem of eternity and glorifies,
in the Christians' eyes, God the Father, the Son and Holy Spirit.

13th fold or when the flag is completely folded, the stars
are uppermost reminding us of our nation's motto,
"In God We Trust."

After the flag is completely folded and tucked in, it takes on the appearance of a cocked hat, ever reminding us of the soldiers who served under General George Washington, and the sailors and marines who served under Captain John Paul Jones, who were followed by their comrades and shipmates in the Armed Forces of the United States, preserving for us the rights, privileges and freedoms we enjoy today. There are some traditions and ways of doing things that have deep meaning. 
In the future, you'll see flags folded and now you will know why. Printing this out and handing a copy to those who would distribute it to school children and/or congregations is appropriate at a time such as we face today. Please share this with the children you love and all others who love what this symbol stands for... by God's grace it will continue to stand thus... for and by "Liberty and Freedom."