That might actually give you less Ukrainians leaving particularly Austrian Galicia, since it was basically kept poor and used as a troop factory. With more of those troops at the front, that's just more people dying, not more people leaving.
You could feasibly win these immigrants, but Ruthenians - since "Ukraine" may be butterflied - largely seemed to prefer Canada, and most of those immigrants came from Austrian Galicia, which at the time was the poorest place in Europe and critically underdeveloped - indeed, Ruthenian farmers in Galicia still used medieval technology. They seemed to prefer the Canadian prairies because Alberta and Saskatchewan have a huge belt of aspen parkland which reminded these immigrants of home - and because of the history of deprivation in Galicia, the Galician peasants coming over tended to preferentially choose forested prairie lands to homestead, because even though the soil was worse, they wouldn't have to pay a landlord for their wood like they did back in the old country. There's significantly more aspen parkland in Canada than there is in the United States.
Theoretically, if you diverted a lot of those immigrants to the United States, I would imagine that many of them would settle out west, and the bulk of them would be Greek Catholic Ruthenian farmers from Galicia and Bukovyna - the wave of immigration would, in other words, have a very agrarian character. The outflow from Orthodox Russian Ruthenia would be comparatively less. A primary settlement area for Galicians taking advantage of the Homestead Acts would almost certainly be northern Minnesota, where the Canadian aspen parkland band extends into. Northern Wisconsin and Michigan, including the top of the mitten, would also be attractive to peasants from Galicia and Bukovyna. You'd probably also get some taking advantage of opportunities to settle in Missouri and Nebraska as focus shifted out there. The result would be that Ruthenian Americans would be a significant ethnic group in the Midwest and many would eventually migrate to cities - I can see Duluth, Green Bay and Traverse City being key hubs of Ruthenian-American culture. As with Canada, their arrival would be treated with suspicion, especially since most Ruthenians who came from Galicia were not only Catholic, but Greek Catholic.
Russian peasants I can imagine preferring to go out west as well, though if more of the immigrants are educated or wealthy Russians - or Russian Jews - they're far more likely to concentrate on the coasts. (Especially Russian Jews liked to settle in coastal cities.) Their arrival will be more urban than the Ruthenians because of the nature of Russians as a ruling class, while Ruthenians tended to be poorer, less educated and more agrarian.
Basically look for a lot of Ruthenian placenames in tiny farm communities throughout the Midwest. Places with names like Halych or Ternopil or Nister or whatever.
P.S.: I don't see there ever being as many Ruthenian-Americans as there are OTL Irish-Americans. The OTL Ukrainian diaspora occurred even with constant famine in Galicia. By some accounts, 50,000 people a year died of starvation. Even OTL, a quarter of the population of Galicia left between 1911 and 1914. Some authors have suggested that the situation there was as bad as, or worse than, that in Ireland. You've got your work cut out for you, in other words, to create worse conditions than what was known as "Galician misery."