Term for aboriginal people of Canada in a historical context

The tribes that inhabited Canada before European contact are generally known as First Nations today. From what I can tell, this term is fairly new.

What term could I use to refer to First Nations people that:

1. can refer to indigenous people from different tribes, and
2. would probably have been understood by someone from the 1800s, and
3. would generally not be offensive to people today?

In the US, for example, the term American Indian meets all three criteria. Is there something similar for Canada?

Try aboriginal (as in the title of your question):

ADJECTIVE

1 (Of human races, animals, and plants) inhabiting or existing in a land from the earliest times or from before the arrival of colonists; indigenous.

MORE EXAMPLE SENTENCES

Around the world, 70 percent of uranium deposits are located on aboriginal land.

As a territory born out of the desire for an aboriginal land claims agreement, we are governed as a public government.

The site will be arranged to evoke the lands where the eleven aboriginal nations in Quebec live.

NOUN

1 An aboriginal inhabitant of a place.

MORE EXAMPLE SENTENCES

Using the aboriginals' own oral histories, the developer proved that the site had been designated sacred only within the past 10 years.

Use aboriginals (not natives) when an all-encompassing collective term is needed.

Women, youth, aboriginals [and] ethnic communities are all in there, but anglophones aren't mentioned anywhere.

Origin

mid 17th century: from Latin aborigines 'original inhabitants' (see aborigine) + -al.

(Definitions, examples and etymology from Oxforddictionaries.com)

indige, aborigine, native -- all refer to original inhabitants of a region (or those first present there).

[But all such terms also apply to anyone born locally. Taken in its pre-1980 (or so) meaning, a native American is anyone born in America.]

However, you are likely to find someone who will be offended, whatever term you choose. If you do not want to offend someone, ask that someone what term they prefer.

FWIW, the same Wikipedia page discusses Canadian terminology.

My first choice would be to use the very word you did: "indigenous". My second choice would be "aboriginal".

I'm a Canadian of European extraction and my understanding of usage is mostly gleaned from casual media consumption and discussions with an older relative who had a senior management role in education in northern Manitoba, where most of the population is Cree. When he was active 10 years ago the preferred term seemed to be "aboriginal" but my impression is that lately the preference leans towards "indigenous".

Both of these derived from Latin and would therefore have presumably been accessible to any educated person in the 19th century. In contemporary Canadian French, the term autochtone (derived from Greek) serves a similar role.

Note that "First Nations" is disqualified for two reasons: first and most importantly, it is a legal term which is explicitly not inclusive of Inuit and Métis, and probably fails your criterion #2.

I don't think the problems with "Indian" need restating. The word "native" on linguistic grounds would seem suitable and AFAIK was the preferred neutral term as recently as a couple decades ago (and is still used that way by many Canadians without intended offence) but in political speech it's become tainted and could be interpreted as pejorative.