Grito de Dolores
¡Mexicanos!
!Que vivan los heroes que nos
Dieron
patria y libertad!
¡Viva Miguel Hidalgo y Costilla
¡Viva Guadalupe Victoria!
¡Viva Ignacio Allende!
¡Viva José María Morelos y Pavón!
¡Via Doña Josefa Ortiz de Domínguez!
¡Que viva México!
¡Que viva México!
¡Que viva México!
Can someone confirm that nos dieron is in fact correct? According to my professor it is a reflexive of dar (I assume darse - to give oneself) but if it is in fact a reflexive wouldn't it be 'se dieron' or 'nos dimos' depending on the context and not 'nos dieron' as it shows on the handout?
semi-flyGrito de Dolores
¡Mexicanos!
!Que vivan los heroes que nos
Dieron
patria y libertad!

¡Viva Miguel Hidalgo y Costilla
¡Viva Guadalupe Victoria!
¡Viva Ignacio Allende!
¡Viva José María Morelos y Pavón!
¡Via Doña Josefa Ortiz de Domínguez!

¡Que viva México!
¡Que viva México!
¡Que viva México!

Can someone confirm that nos dieron is in fact correct? According to my professor it is a reflexive of dar (I assume darse - to give oneself) but if it is in fact a reflexive wouldn't it be 'se dieron' or 'nos dimos' depending on the context and not 'nos dieron' as it shows on the handout?

I don't think your professor is right. Althoug the reflexive verb darse exist, it is not being as used reflexing pronoun. The nos is being used as a direct object. In my opinion, it is fine that sense. However, I'm not sure if the whole sentences actually makes sense. You can not give patria to somebody. Also you should attach the definite article to the noun. Definite articles are used much much more often in Spanish than in English. The sentence should read something like this:

¡Que vivan los héroes que nos libraron/dieron la libertad!
According to the handout the poem translates as follows:
Mexicans!
Long live the heroes who gave us
homeland and liberty!
Long live Miguel Hidalgo y Costilla!
Long live Guadalupe Victoria!
Long live Ignacio Allende!
Long live José M. Morelos y Pavón!
Long live Doña Josefa Ortiz de Domínquez!
Long live Mexico!
Long live Mexico!
Long live Mexico!
But even if 'nos' is used as a direct object pronoun (DOp) should it not also be followed by a verb that has been conjugated to match the DOp?
Mexicans!
Long live the heroes who gave us
homeland and liberty!

Mexicanos
Larga vida a los héroes que nos dieron
Patria y Libertad!

"nos dieron" is right.

Can someone confirm that nos dieron is in fact correct? According to my professor it is a reflexive of dar (I assume darse - to give oneself) but if it is in fact a reflexive wouldn't it be 'se dieron' or 'nos dimos' depending on the context and not 'nos dieron' as it shows on the handout?

I'll try to write examples
They give us some food------ Ellos nos dieron algo de comida
They(heroes) give us liberty-----Ellos nos dieron libertad.

"se dieron" is to give themselves
"nos dimos " is to give ourselves
"Nos" is not used as a direct object, it's an indirect object (it's right if I say "but a indirect object"?). So it is not a reflexive pronoun, because as you said, the reflexives pronoun have to be in the same person than the subject.
It is not a reflexive...the NOS means "to us" the heroes gave us freedom...so it is the Indirect Object Pronoun