Algol-60 gave us:
- semicolons as statement terminators
- begin/end
- chain assignment (a := b := c)
- conditional expressions (like ?: in C)
- the "type name;" variable declaration syntax.
- while loops (technically both "while" and "for" were syntactic elements of a single loop structure, and could be combined)
Algol-68 mostly influenced other languages via C, which appropriated quite a few of its keywords: void; struct; union; long and short (in A68, you could chain arbitrarily many "long" and "short" before "int" or "real" - the implementations were required to distinguish short int / int / long int, but additional modifiers could be used in an implementation-defined way to designate larger or smaller types if an implementation chose to provide them - if there was a need for 128-bit ints, for example, they'd be "long long long int"). Abbreviated type names as well: int, char, bool all come from A68. Also, compound assignment like += and -= (except it was +:= and -:=), and the notion of assignments as expressions yielding the assigned value.
Go arguably takes the consistently left-to-right composite type syntax from A68: arrays were declared as e.g. [0:9]int, although variable name still followed type. Something like "ref []bool x" would mean "x is a pointer to an array of Booleans".
Regarding := specifically, it was an assignment operator in Algol-60 (and thence in Pascal language family). In Algol-68, you would use = to initialize an immutable variable in a declaration, and := to assign to them if they are mutable, while Go is the reverse.
Bourne shell took reversed-spelling terminator keywords like "fi", "od", "esac" etc from A68.
C++ seems to have gotten its operator overloading from A68.
It's very interesting to read both specs today. Even Algol-60 was amazingly powerful in some respects - it already had nested functions closing over outer function's variables, and functions passed as arguments, for example (although they weren't first-class, since you couldn't return functions). Then there was crazy stuff like call-by-name, computed gotos, and passing labels as arguments (to which the callee could then goto across stack frames! basically, setjmp/longjmp as an intrinsic language feature). It can be an interesting exercise to try to devise an efficient implementation of all this stuff.
And Algol-68 pretty much reads as a modern programming language, except for some weird terminology that they invented just for it that didn't get adopted by the industry - e.g. "transput" for input and output, or "mode" for types. From modern perspective, it's hard to understand why it was considered overcomplicated in its day, but it makes more sense when you look at its competitors at the time. The most funky thing about it from modern perspective is that pointers were implicitly dereferenced, and so it needed to have a bunch of extra operators to disambiguate things (e.g. "=" for value equality with implicit dereferencing, and "is" for pointer equality).
Here are the actual reports, for those curious. This one is for Algol-60, as revised in 1963 (there was a later "modified report" in 1975, which codified a bunch of extensions and features standardized elsewhere - but reading the original reports is more interesting given the historical context):
https://www.masswerk.at/algol60/report.htm
And this is for Algol-68.
http://www.math.bas.bg/bantchev/place/algol68/a68rr.html
but it's a rather heavy read, being wrong and using a lot of peculiar jargon. For something more accessible, try this: