Declaration of the National Anti-Slavery Convention was written by William Lloyd Garrison for the formation of the American Anti-Slavery Society in December 1833. It was reprinted in The Liberator on December 14, 1833. It is now available in the Public Domain.
You can also use the Optimized PDF option to crank the size down in very targeted ways. Given the big before/after shift, the culprit is probably the image you're embedding. Try exporting that file in various formats (PDF, jpg, png) and then import it.
Important: Once you have saved a document as a PDF file, you cannot convert it back to a Microsoft Office file format without specialized software or a third-party add-in. To save a file in .pdf format: 1. Open the document you want to save as a .pdf. 2. Click the File tab. 3. Click Save As (choosing Save As keeps your original version and saves a copy of it in .pdf format) 4. In the File Name box, enter a name for the file if you haven't already.