These are all the same stamp, there is often slight variations in stamp colors (especially 'used' stamps). Things to look at the a perforations. Note some of the above are not perforated on one or more sides, in this case these are probably from a booklet pane of six stamps. This stamp was one of the workhorses of the era and printed in the millions, it is called a 'definitive'. Those larger stamp which honor a person or event are typically called 'commemoratives'.
Note about perforations...In some cases, if there are not any perfs on parallel
sides, they are called 'coil' stamps and were typically dispensed from a roll in a machine.
Stamps often have different perforations, so you must use a perforation gauge to understand which stamp you have. If you do not have one, you can download a free paper one here for now.http://stampsmarter.com/learning/Fo...rfGauge.html
You can learn a lot more, including IDing many of your stamps here http://stampsmarter.com/1847usa/1847HomeDef.html
There is also a two other learning resources which may be helpful. The first is an illustrated Glossary here http://www.stampsmarter.com/Learnin...aryHome.html
And there is a "How To" section here http://www.stampsmarter.com/learnin...e_HowTo.html