The population of veterans waiting for verdicts on their disability claims, about 816,839 people, is larger than that of four states — Alaska, North Dakota, Vermont and Wyoming — as well as of the District of Columbia.

About two-thirds of these claims have been pending for more than 125 days, which makes them part of the Department of Veterans Affairs’ daunting backlog. The long wait has withstood a VA effort that has seen the agency handle more than 3 million claims in the past three fiscal years. VA Secretary Eric Shinseki this year pledged to eliminate what he calls the “decades-old problem” of the backlog by 2015, with no claim taking longer than 125 days to process by that time.

The secretary in recent years both contributed to a temporary swell in the backlog and then devoted resources to dispatch it.

Shinseki in 2010 opted to expand the condition for which Vietnam War veterans could claim disability payments due to potential Agent Orange exposure to include Parkinson’s disease and a common condition, ischemic heart disease. That helped triggered a surge in 2011 of more than 230,778 claims related to the expansion.

By June 2012, Shinseki announced the VA had dispatched most of the claims related to the expansion of benefits, providing $3.6 billion for veterans and their survivors. The VA’s Benefits Administration had devoted its most experienced decision-makers, about 37 percent of its rating staff, to processing Agent Orange claims.