It is #EnigMarch, and when they challenge us to design a puzzle, I ask "how high?"

In the three sequences below, you will grow words. You'll start with a two-letter word, then add a letter to get the next word; another letter to get the next-next word, and so on. (Some of these words are proper names and/or foreign, but I hope they're get-able.) There's no anagramming, just inserting a letter.

Indefinite article:	_ _
	◯ _ _
	◯ _ _ _
Agrippa, Brutus, or Cicero:	_ _ _ _ _
	_ _ _ _ _ ◯
Nicholas II's family:	_ _ _ _ _ _ _
☙ ❧
It's north of RI in USA:	_ _
	_ _ ◯
	_ _ _ ◯
Inventor Curie:	_ _ _ _ _
Sea-related:	_ _ _ _ _ _
	_ _ _ _ _ _ ◯
Seattle team:	_ _ _ _ _ _ _ _
☙ ❧
¿Quién __ más macho?:	_ _
	◯ _ _
	◯ _ _ _
Alan, Barbara, Nathan, et al:	_ _ _ _ _
	◯ _ _ _ _ _
Hartford NHL team:*	_ _ _ _ _ _ _

*This one's for you, Tyler.

Sometimes the added-letter goes in a circle instead of a blank. When you're done, the circled letters spell out something growth-related that's been on my mind lately: ◯ ◯ ◯ ◯ ◯'◯ ◯ ◯ ◯

Rot13'd answers:

Vaqrsvavgr negvpyr     na
                     Z zna
		     B Bzna
Ntevccn be Oehghf      ebzna
                     B ebznaB
Avpubynf VV            ebznabi		       

Vg'f abegu bs EV       zn
                     E znE
                     R zneR
Vairagbe Phevr         znevr
Frn-eryngrq            znevar
                     F znevarF
Frnggyr grnz           znevaref

¿Dhvéa __ záf znpub?   rf
                     Y Yrf
                     N Nyrf
Nyna, Oneonen          unyrf
                     J Junyrf
Unegsbeq AUY grnz      junyref

Gur pvepyrq yrggref fcryy: Zbber'f Ynj