Was the united states justified in going to war against spain in 1898

Yes, and the US made sure it was justfied and they weren't just trying to take land away from Spain. Cuba had been revolting against Spain and the US supported that because they didn't want a European power to be near them. They didn't give them military support but they supported the idea. They also signed some law that said that if Cuba was freed from Spain that it would not become a US territory and they held up their end of the deal. The only thing the US got out of it was Guantanamo Bay prison.

What sparked the war was the sinking of the USS Maine and at the time when an investigation had not occured they felt the Spanish had sunk it and they were 100% justified at the time to go to war with Spain. But 100 years later they did an investigation and saw that the Ships metal was bent outwards instead of inwards which ruled out an exterior attack. This meant that the explosion came from within the ship. They theorized that somehow a spark hit bunch of gun powder and that set the explosion of that sunk the ship. But at the time there was no way to know that and because of the tension with Spain it seemed like an attack.