Dear (recipient's name),
On (date), I will be joining people from nearly (number) cities nationwide who are working to benefit (organization). Last year the national total was over $(amount) and here in city we raised nearly $(amount) alone!
I am asking for your help in my endeavor. By making a pledge on my behalf, you will fund research projects to help find (organization). My goal is to raise $(amount) for (organization). Please help me achieve this goal by making a tax deductible contribution to the (organization). For your convenience, I have enclosed an envelope to make giving easy. Please make checks payable to the (organization) and reference my name on them. If you would prefer to make a donation using your MasterCard or Visa, please feel free to do so by contacting the (organization) office at (phone number); just make sure that you let them know that the donation should go in support of my fundraising efforts.
Thank you for your support in this cause that is so important to me.
Sincerely,
(your name)