Congress, First Amendment. Do not capitalize adjectives, ie. congressional, religious. The President has presidential powers. The use of an apostrophe to signal a plural noun is strictly verboten. The lack of an apostrophe in a possessive noun will be punished.
Punctuation belonging to a quote belongs inside of the quotation marks.
A word is a terrible thing to waste. If you do not own a copy, buy one. Read it while revising your own work. It will serve you well. For a better understanding of grammar, please refer to Margaret Shertzer, The Elements of Grammar or to any recent edition of the Merriam-Webster Collegiate Dictionary , which contains a section on proper usage.