Back on May 23, 2010 I blogged about Speechwriting advice U.S. Citizens already have paid for and referred to Speechwriting in Perspective: A Brief Guide to Effective and Persuasive Communication which is Congressional Research Service Report #98-170 which you can download as a 26-page .pdf file here or here.
When I recently did a Google search I also found two brief documents. One is Speechwriting Resources: Fact Sheet (their R44239 from November 4, 2015) which can be downloaded here. It refers to Finding Quotes for Speeches: Fact Sheet (their CRS Report R44200) which can be downloaded here.
An image of the U.S. Capitol came from Wikimedia Commons.