Major historical events like war or military service make a lasting impact on family identity often reverberating across multiple generations. (Family Features) Veterans frequently speak about their military units as if they were family, given the unbreakable bonds that develop between comrades. However, for some veterans, “brothers in arms” is more than a figurative turn of phrase. Throughout the 20th century, entire families felt the firsthand effects of war, with multiple generations serving. Brothers enlisted together. A father’s military legacy…