U.S. Marine reservist Lance Cpls. Wilbert Allen, left, and Christopher Morehouse tend to their M-198 howitzer early May 2, the opening day of this year's Public Service Recognition Week exhibits on the National Mall in Washington, D.C. Photo by Gerry J. Gilmore U.S. Marine reservist Lance Cpls. Wilbert Allen, left, and Christopher Morehouse tend to their M-198 howitzer early May 2, the opening day of this year's Public Service Recognition Week exhibits on the National Mall in Washington, D.C. Photo by Gerry J. Gilmore SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 760045-D-CKV35-736.jpg Photo Gallery