Here's your 2015 Astros Opening Day roster, and from where exactly these guys came...
Pitchers
Sam Deduno: Selected off waivers from Twins, 8/30/2014
Scott Feldman: Signed as free agent, 12/6/2013
Luke Gregerson: Signed as free agent, 12/12/2014
Will Harris: Selected off waivers from D'Backs, 11/3/2014
Roberto Hernandez: Signed as free agent, 2/12/2015
Dallas Keuchel: Drafted, 7th Round of 2009 draft
Collin McHugh: Selected off waivers from Rockies, 12/18/2013
Pat Neshek: Signed as free agent, 12/12/2014
Chad Qualls: Signed as free agent, 12/7/2013
Tony Sipp: Signed as free agent, 5/1/2014
Joe Thatcher: Signed as free agent, 2/13/2015
Asher Wojciechowski: Acquired in 10-player trade with Blue Jays, 7/20/2012
Catchers
Jason Castro: Drafted, 1st Round of 2008 draft
Hank Conger: Acquired in trade with Angels for Carlos Perez and Nick Tropeano, 11/5/2014
Evan Gattis: Acquired in trade with James Hoyt from Braves for Mike Foltynewicz, Rio Ruiz, and Andrew Thurman, 1/14/2015
Infielders
Jose Altuve: Signed as amateur free agent, 3/6/2007
Marwin Gonzalez: Essentially taken in Rule 5 draft, 12/8/2011
Jed Lowrie: Signed as free agent, 12/15/2014
Luis Valbuena: Acquired via trade with Cubs for Dexter Fowler, 1/19/2015
Jonathan Villar: Acquired via trade with Phillies for Roy Oswalt, 7/29/2010
Outfielders
Robbie Grossman: Acquired via trade with Pirates for Wandy Rodriguez, 7/24/2012
Jake Marisnick: Acquired via trade with Colin Moran, Frances Martes, and 2015 Compensation Pick with Marlins for Jarred Cosart, Austin Wates, and Enrique Hernandez, 7/31/2014
Colby Rasmus: Signed as free agent, 1/20/2015
George Springer: Born as the human child of a secret illicit tryst between a unicorn and a 19th century strongman, was dropped off at the front door of Minute Maid Park, 2011
Designated Hitter
Chris Carter: Acquired via trade with Athletics for Jed Lowrie and Fernando Rodriguez, 2/4/2013
Transaction Breakdown
*Signed via Free Agency: 9
*Acquired through Trade: 8
*Selected as Waiver Claims: 3
*Drafted: 3
*Signed as Amateur free agent: 1
*Selected in Rule 5 draft: 1